Principles of Geology, by Charles Lyell

Principles of Geology, by Charles Lyell

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PRINCIPLES OF GEOLOGY -- BEING AN ATTEMPT TO EXPLAIN THE FORMER CHANGES OF THE EARTH'S SURFACE, BY REFERENCE TO CAUSES NOW IN OPERATION -- VOLUMES 1, 2 & 3
by Charles Lyell, Esq., F.R.S.
For Sec. to the Geol. Soc., &c.
© 1990 The University of Chicago

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"Amid all the revolutions of the globe the economy of Nature has been uniform, and her laws are the only things that have resisted the general movement. The rivers and the rocks, the seas and the continents have been changed in all their parts; but the laws which direct those changes, and the rules to which they are subject, have remained invariably the same." -- PLAYFAIR, Illustrations of the Huttonian Theory, § 374.

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Table of Contents:

• Volume 1
• Introduction, by Martin J. S. Rudwick
• Volume 1
o Front Matter
o Chapter 1: Geology defined – Compared to History – Its relation to other Physical Sciences – Its distinctness from all – Not to be confounded with Cosmogony
o Chapter 2: Oriental Cosmogony – Doctrine of the successive destruction and renovation of the world – Origin of this doctrine – Common to the Egpytians – Adopted by the Greeks – System of Pythagoras – Of Aristotle – Dogmas concerning the extinction and reproduction of genera and species – Strabo's theory of elevation by earthquakes – Pliny – Concluding remarks on the knowledge of the Ancients
o Chapter 3: Arabian writers of the Tenth century – Persecution of Omar – Cosmogony of the Koran – Early Italian writers – Fracastoro – Controversy as to the real nature of organized fossils – Fossil shells attributed to the Mosaic deluge – Palissy – Steno – Scilla – Quirini – Boyle – Plot – Hooke's Theory of Elevation by earthquakes – His speculations on lost species of animals – Ray – Physico-theological writers – Woodward's Diluvial Theory – Burnet – Whiston – Hutchinson – Leibnitz – Vallisneri – Lazzoro Moro – Generelli – Buffon – His theory condemned by the Sorbonne as unorthodox – Buffon's declaration – Targioni – Ardinino – Michell – Catcott – Raspe – Fortis – Testa – Whitehurst – Pallas – Saussure
o Chapter 4: Werner's application of Geology to the art of Mining – Excursive character of his lectures – Enthusiasm of his pupils – His authority – His theoretical errors – Desmarest's map and description of Auvergne – Controversy between the Vulcanists and Neptunists – Intemperance of the rival Sects – Hutton's theory of the Earth – His discovery of granite veins – Originality of his views – Why opposed – Playfair's illustrations – Influence of Voltaire's writings on Geology – Imputations cast on the Huttonians by Williams, Kirwau, and De Luc – Smith's map of England – Geological Society of London – Progress of the Science in France – Growing importance of the study of organic remains
o Chapter 5: Review of the causes which have retarded the progress of Geology – Effects of prepossessions in regard to the duration of past time – Of prejudices arising from our peculiar position as inhabitants of the land – Of those occasioned by our not seeing subterranean changes now in progress – All these causes combine to make the former course of Nature appear different from the present – Several objections to the assumption, that existing causes have produced the former changes of the earth's surface, removed by modern discoveries
o Chapter 6: Proofs that the climate of the Northern hemisphere was formerly hotter – Direct proofs from the Organic remains of the Sicilian and Italian strata – Proofs from analogy derived from extinct Quadrupeds – Imbedding of Animals in Icebergs – Siberian Mammoths – Evidence in regard to temperature, from the fossil remains of tertiary and secondary rocks – From the plants of the coal formation
o Chapter 7: On the causes of vicissitudes in climate – Remarks on the present diffusion of heat over the globe – On the dependence of the mean temperature on the relative position of land and sea – Isothermal lines – Currents from equatorial regions – Drifting of Icebergs – Different temperature of Northern and Southern hemispheres – Combination of causes which might produce the extreme cold of which the earth's surface is susceptible – On the conditions necessary for the production of the extreme of heat, and its probable effects on organic life
o Chapter 8: Geological proofs that the geographical features of the northern hemisphere, at the period of the deposition of the carboniferous strata, were such as would, according to the theory before explained, give rise to an extremely hot climate – Origin of the transition and mountain limestones, coal-sandstones, and coal – Change in the physical geography of northern latitudes, between the era of the formation of the carboniferous series and the lias – Character of organic remains, from the lias to the chalk inclusive – State of the surface when these deposits originated – Great accession of land, and elevation of mountain-chains, between the consolidation of the newer secondary and older tertiary rocks – Consequent refrigeration of climate – Abrupt transition from the organic remains of the secondary to those of the tertiary strata – Maestricht beds – Remarks on the theory of the diminution of central heat
o Chapter 9: Theory of the progressive development of organic life considered – Evidence in its support wholly inconclusive – Vertebrated animals in the oldest strata – Differences between the organic remains of successive formations – Remarks on the comparatively modern origin of the human race – The popular doctrine of successive development not confirmed by the admission that man is of modern origin – In what manner the change in the system caused by the introduction of man affects the assumption of the uniformity of the past and future course of physical events
o Chapter 10: Division of the subject into changes of the organic and inorganic world – Inorganic causes of change divided into the aqueous and igneous – Aqueous causes – Destroying and transporting power of running water – Sinuosities of rivers – Two streams when united do not occupy a bed of double surface – Heavy matter removed by torrents and floods – Recent inundations in Scotland – Effects of ice in removing stones – Erosion of chasms through hard rocks – Excavations in the lavas of Etna by Sicilian rivers – Gorge of the Simeto – Gradual recession of the cataracts of Niagara – Speculations as to the time required for their reaching Lake Erie
o Chapter 11: Action of running water, continued – Course of the Po – Desertion of its old channel – Artificial embankments of the Po, Adige, and other Italian rivers – Basin of the Mississippi – Its meanders – Islands – Shifting of its course – Raft of the Atchafalaya – Drift wood – New-formed lakes in Louisiana – Earthquakes in the valley of the Mississippi – Floods caused by landslips in the White mountains – Bursting of a lake in Switzerland – Devastations caused by the Anio at Tivoli
o Chapter 12: Difference between the transporting power of springs and rivers – Many springs carry matter from below upwards – Mineral ingredients most abundant in springs – Connexion of mineral waters with volcanic phenomena – Calcareous springs – Travertin of the Elsa – Baths of San Vignone, and of San Filippo, near Radicofani – Spheroidal structure in travertin, as in English magnesian limestone – Bulicami of Viterbo – Lake of the Solfatara, near Rome – Travertin at Cascade of Tivoli – Ferruginous springs – Cementing and colouring property of iron – Brine springs – Carbonated springs – Disintegration of Auvergne granite – Caverns in limestone – Petroleum springs – Pitch lake of Trinidad
o Chapter 13: Reproductive effects of running water – Division of deltas into lacustrine, mediterranean, and oceanic – Lake deltas – Growth of the delta of the Rhone in the Lake of Geneva – Chronological computations of the age of deltas – Recent deposits in Lake Superior – Deltas of inland seas – Rapid shallowing of the Baltic – Arguments for and against the hypothesis of Celsius – Elevated beaches on the coast of Sweden – Marine delta of the Rhone – Various proofs of its increase – Stony nature of its deposits – Delta of the Po, Adige, Isonzo, and other rivers entering the Adriatic – Rapid conversion of that gulf into land – Mineral characters of the new deposits – Delta of the Nile – Its increase since the time of Homer – Its growth why checked at present
o Chapter 14: Oceanic deltas – Delta of the Ganges and Burrampooter – Its size, rate of advance, and nature of its deposits – Formation and destruction of islands – Abundance of crocodiles – Inundations – Delta of the Mississippi – Deposits of drift wood – Gradual filling up of the Yellow Sea – Rennell's estimate of the mud carried down by the Ganges – Formation of valleys illustrated by the growth of deltas – Grouping of new strata in general – Convergence of deltas – Conglomerates – Various causes of stratification – Direction of laminae – Remarks on the interchange of land and sea
o Chapter 15: Destroying and transporting effects of Tides and Currents – Shifting of their position – Differences in the rise of the tides – Causes of currents – Action of the sea on the British coast – Shetland Islands – Large blocks removed – Effects of lightning – Breach caused in a mass of porphyry – Isles reduced to clusters of rocks – Orkney Isles – East coast of Scotland – Stones thrown up on the Bell Rock – East coast of England – Waste of the cliffs of Holderness, Norfolk, and Suffolk – Silting up of Estuaries – Origin of submarine forests – Yarmouth estuary – Submarine forests – Suffolk coast – Dunwich – Essex coast – Estuary of the Thames – Goodwin Sands – Coast of Kent – Formation of Straits of Dover – Coast of Hants – Coast of Dorset – Portland – Origin of the Chesel Bank – Cornwall – Lionnesse tradition – Coast of Brittany
o Chapter 16: Action of Tides and Currents, continued – Inroads of the sea upon the delta of the Rhine in Holland – Changes in the arms of the Rhine – Estuary of the Bies Bosch, formed in 1421 – Formation of the Zuyder Zee, in the 13th century – Islands destroyed – Delta of the Ems converted into a bay – Estuary of the Dollart formed – Encroachment of the sea on the coast of Sleswick – Inroads on the eastern shores of North America – Tidal wave called the Bore – Influence of tides and currents on the mean level of seas – Action of currents on inland lakes and seas – Baltic – Cimbrian deluge – Straits of Gibraltar – Under currents – Shores of Mediterranean – Rocks transported on floating icebergs – Dunes of blown sand – Sands of the Libyan Desert – De Luc's natural chronometers
o Chapter 17: Reproductive effects of Tides and Currents – Silting up of Estuaries does not compensate the loss of land on the borders of the ocean – Bed of the German Ocean – Composition and extent of its sand-banks – Strata formed by currents on the southern and eastern shores of the Mediterranean – Transportation by currents of the sediment of the Amazon, Orinoco, and Mississippi – Stratification – Concluding remarks
o Chapter 18: Division of igneous agents into the volcano and the earthquake – Distinct regions of subterranean disturbance – Region of the Andes – System of volcanos extending from the Aleutian Isles to the Moluccas – Polynesian archipelago – Volcanic region extending from the Caspian Sea to the Azores – Former connexion of the Caspian with Lake Aral and the Sea of Azof – Low steppes skirting these seas – Tradition of deluges on the shores of the Bosphorus, Hellespont, and the Grecian archipelago – Periodical alternation of earthquakes in Syria and Southern Italy – Western limits of the European region – Earthquakes rarer and more feeble in proportion as we recede from the centres of volcanic action – Extinct volcanos not to be included in lines of active vents
o Chapter 19: History of the volcanic eruptions in the district round Naples – Early convulsions in the island of Ischia – Numerous cones thrown up there – Epomeo not an habitual volcano – Lake Avernus – The Solfatara – Renewal of the eruptions of Vesuvius A.D. 79 – Pliny's description of the phenomena – Remarks on his silence respecting the destruction of Herculaneum and Pompeii – Subsequent history of Vesuvius – Lava discharged in Ischia in 1302 – Pause in the eruptions of Vesuvius – Monte Nuovo thrown up – Uniformity of the volcanic operations of Vesuvius and the Phlegraean Fields in ancient and modern times
o Chapter 20: Dimensions and structure of the cone of Vesuvius – Dikes in the recent cone, how formed – Section through Vesuvius and Somma – Vesuvian lavas and minerals – Effects of decomposition of lava – Alluvions called "aqueous lavas" – Origin and composition of the matter enveloping Herculaneum and Pompeii – Controversies on the subject – Condition and contents of the buried cities – Proofs of their having suffered by an earthquake – Small number of skeletons – State of preservation of animal and vegetable substances – Rolls of Papyrus – Probability of future discoveries of MSS. – Stabiae – Torre del Greco – Concluding remarks on the destroying and renovating agency of the Campanian volcanos
o Chapter 21: External physiognomy of Etna – Minor cones produced by lateral eruptions – Successive obliteration of these cones – Early eruptions of Etna – Monti Rossi thrown up in 1669 – Great fissure of S. Lio – Towns overflowed by lava – Part of Catania destroyed – Mode of the advance of a current of lava – Excavation of a church under lava – Series of subterranean caverns – Linear direction of cones formed in 1811 and 1819 – Flood produced in 1755 by the melting of snow during an eruption – A glacier covered by a lava stream on Etna – Volcanic eruptions in Iceland – New island thrown up in 1783 – Two lava-currents of Skaptár Jokul in the same year – Their immense volume – Eruption of Jorullo in Mexico – Humboldt's Theory respecting the convexity of the Plain of Malpais
o Chapter 22: Volcanic Archipelagos – The Canaries – Eruptions of the Peak of Teneriffe – Cones thrown up in Lancerote in 1730-36 – Pretended distinction between ancient and modern lavas – Recent formation of oolitic travertine in Lancerote – Grecian Archipelago – Santorin and its contiguous isles – Von Buch's Theory of "Elevation Craters" considered – New islands thrown up in the Gulf of Santorin – Supposed "Crater of Elevation" in the Isle of Palma – Description of the Caldera of Palma – Barren island in the Bay of Bengal – Origin of the deep gorge on the side of "Elevation Craters" – Stratification of submarine volcanic products – Causes of the great size of the craters of submarine volcanos – Cone of Somma, formed in the same manner as that of Vesuvius – Mineral composition of volcanic products – Speculations respecting the nature of igneous rocks produced at great depths, by modern volcanic eruptions
o Chapter 23: Earthquakes and their effects – Deficiency of ancient accounts – Ordinary atmospheric phenomena – Changes produced by earthquakes in modern times considered in chronological order – Earthquake in Murcia, 1829 – Bogota in 1827 – Chile in 1822 – Great extent of country elevated – Aleppo in 1822 – Ionian Isles in 1820 – Island of Sumbawa in 1815 – Town of Tomboro submerged – Earthquake of Cutch in 1819 – Subsidence of the delta of the Indus – Earthquake of Caraccas in 1812 – South Carolina in 1811 – Geographical changes in the valley of the Mississippi – Volcanic convulsions in the Aleutian Islands in 1806 – Reflections on the earthquakes of the eighteenth century – Earthquake in Quito, 1797 – Cumana, 1797 – Caraccas, 1790 – Sicily, 1790 – Java, 1786 – Sinking down of large tracts
o Chapter 24: Earthquake in Calabria, February 5th, 1783 – Shocks continued to the end of the year 1786 – Authorities – Extent of the area convulsed – Geological structure of the district – Difficulty of ascertaining changes of relative level even on the sea-coast – Subsidence of the quay at Messina – Shift or fault in the Round Tower of Terranuova – Movement in the stones of two obelisks – Alternate opening and closing of fissures – Cause of this phenomenon – Large edifices engulphed – Dimensions of new caverns and fissures – Gradual closing in of rents – Bounding of detached masses into the air – Landslips – Buildings transported entire, to great distances – Formation of fifty new lakes – Currents of mud – Small funnel-shaped hollows in alluvial plains – Fall of cliffs along the sea-coast – Shore near Scilla inundated – State of Stromboli and Etna during the shocks – Illustration afforded by this earthquake of the mode in which valleys are formed
o Chapter 25: Earthquakes of the eighteenth century, continued – Java, 1772 – Truncation of a lofty cone – Caucasus, 1772 – Java, 1771 – Colombia, 1766 – Chile, 1760 – Azores, 1757 – Lisbon, 1755 – Sinking down of the quay to the depth of six hundred feet – Shocks felt throughout Europe, Northern Africa, and the West Indies – Great wave – Shocks felt at sea – St. Domingo, 1751 – Conception Bay, 1750 – Permanent elevation of the bed of the sea to the height of twenty-four feet – Peru, 1746 – Kamtschatka, 1737 – Martinique, 1727. Iceland, 1725 – Teneriffe, 1706 – Java, 1699 – Landslips obstruct the Batas vian and Tangaran rivers – Quito, 1698 – Sicily, 1693 – Subsidence of land – Moluccas,1693 – Jamaica,1692 – Large tracts engulphed – Portion of Port Royal sunk from twenty to fifty feet under water – The Blue Mountains shattered – Reflections on the amount of change in the last one hundred and forty years – Proofs of elevation and subsidence of land on the coast of the Bay of Baise – Evidence of the same afforded by the present state of the Temple of Serapis
o Chapter 26: Magnitude of the subterranean changes produced by earthquakes at great depths below the surface – Obscurity of geological phenomena no proof of want of uniformity in the system, because subterranean processes are but little understood – Reasons for presuming the earthquake and volcano to have a common origin – Probable analogy between the agency of steam in the Icelandic geysers, and in volcanos during eruptions – Effects of hydrostatic pressure of high columns of lava – Of the condensation of vapours in the interior of the earth – That some earthquakes may be abortive eruptions – Why all volcanos are in islands or maritime tracts – Gases evolved from volcanos – Regular discharge of heat and of gaseous and earthy matter from the subterranean regions – Cause of the wave-like motion and of the retreat of the sea during earthquakes – Difference of circumstances of heat and pressure at great depths – Inferences from the superficial changes brought about by earthquakes – In what matter the repair of land destroyed by aqueous causes takes place – Proofs that the sinking in of the earth's crust somewhat exceeds the forcing out by earthquakes – Geological consequences of this hypothesis, that there is no ground for presuming that the degree of force exerted by subterranean movements in a given time has diminished – Concluding remarks
o Index (Part 1)
o Index (Part 2)

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Table of Contents:

• Volume 2
o Front Matter
o Chapter 1: Changes of the Organic World now in progress – Division of the Subject – Examination of the question, Whether Species have a real existence in Nature? – Importance of this question in Geology – Sketch of Lamarck's arguments in favour of the Transmutation of Species, and his conjectures respecting the Origin of existing Animals and Plants – His Theory of the transformation of the Orang Outang into the Human Species
o Chapter 2: Recapitulation of the arguments in favour of the theory of transmutation of species – Their insufficiency – The difficulty of discriminating species mainly attributable to a defective knowledge of their history – Some mere varieties possibly more distinct than certain individuals of distinct species – Variability in a species consistent with a belief that the limits of deviation are fixed – No facts of transmutation authenticated – Varieties of the Dog – The Dog and Wolf distinct Species – Mummies of various animals from Egypt identical in character with living individuals – Seeds and plants from the Egyptian tombs – Modifications produced in plants by agriculture and gardening
o Chapter 3: Variability of a species compared to that of an individual – Species which are susceptible of modification may be altered greatly in a short time, and in a few generations; after which they remain stationary – The animals now subject to man had originally an aptitude to domesticity – Acquired peculiarities which become hereditary have a close connexion with the habits or instincts of the species in a wild state – Some qualities in certain animals have been conferred with a view of their relation to man – Wild elephant domesticated in a few years, but its faculties incapable of further development
o Chapter 4: Consideration of the question whether species have a real existence in nature, continued – Phenomena of hybrids – Hunter's opinions as to mule animals – Mules not strictly intermediate between the parent species – Hybrid plants – Experiments of Kölreuter – The same repeated by Wiegmann – Vegetable hybrids prolific throughout several generations – Why so rare in a wild state – Decandolle's opinion respecting hybrid plants – The phenomena of hybrids confirms the doctrine of the permanent distinctness of species – Theory of the gradation in the intelligence of animals as indicated by the facial angle – Discovery of Tieddemann that the brain of the foetus in mammalia assumes successively the form of the brain of a fish, reptile, and bird – Bearing of this discovery on the theory of progressive development and transmutation – Recapitulation
o Chapter 5: Laws which regulate the geographical distribution of species – Analogy of climate not attended with identity of species – Botanical geography – Stations – Habitations – Distinct provinces of indigenous plants – Vegetation of islands – Marine vegetation – In what manner plants become diffused – Effects of wind, rivers, marine currents – Agency of animals – Many seeds pass through the stomachs of animals and birds undigested – Agency of man in the dispersion of plants, both voluntary and involuntary – Its analogy to that of the inferior animals
o Chapter 6: Geographical distribution of Animals – Buffon on the specific distinctness of the quadrupeds of the old and new world – Different regions of indigenous mammalia – Quadrupeds in islands – Range of the Cetacea – Dissemination of quadrupeds – Their powers of swimming – Migratory instincts – Drifting of quadrupeds on ice-floes – On floating islands of drift-timber – Migrations of Cetacea – Habitations of Birds – Their migrations and facilities of diffusion – Distribution of Reptiles and their powers of dissemination
o Chapter 7: Geographical distribution and migrations of fish – Of testacea – Causes which limit the extension of many species – Their mode of diffusion – Geographical range of zoophytes – Their powers of dissemination – Distribution of insects – Migratory instincts of some species – Certain types characterize particular countries – Their means of dissemination – Geographical distribution and diffusion of man – Speculations as to the birth-place of the human species – Progress of human population – Drifting of canoes to vast distances – On the involuntary influence of man in extending the range of many other species
o Chapter 8: Theories respecting the original introduction of species – Proposal of an hypothesis on this subject – Supposed centres or foci of creation – Why the distinct provinces of animals and plants have not become more blended together – Brocchi's speculations on the loss of species – Stations of plants and animals – Complication of causes on which they depend – Stations of plants, how affected by animals – Equilibrium in the number of Species, how preserved – Peculiar efficacy of insects in this task – Rapidity with which certain insects multiply, or decrease in numbers – Effect of omnivorous animals in preserving the equilibrium of species – Reciprocal influence of aquatic and terrestrial species on each other
o Chapter 9: The circumstances which constitute the Stations of Animals are changeable – Extension of the range of one species alters the condition of others – Supposed effects which may have followed the first entrance of the Polar Bears into Iceland – The first appearance of a new species in a region causes the chief disturbance – Changes known to have resulted from the advance of human population – Whether man increases the productive powers of the earth – Indigenous Quadrupeds and Birds of Great Britain known to have been extirpated – Extinction of the Dodo – Rapid propagation of the domestic Quadrupeds over the American Continent – Power of exterminating species no prerogative of Man – Concluding Remarks
o Chapter 10: Influence of inorganic causes in changing the habitations of species – Powers of diffusion indispensable, that each species may maintain its ground – How changes in the physical geography affect the distribution of species – Rate of the change of species cannot be uniform, however regular the action of the inorganic causes – Illustration derived from subsidences by earthquakes – From the elevation of land by the same – From the formation of new islands – From the wearing through of an isthmus – Each change in the physical geography of large regions must occasion the extinction of species – Effects of a general alteration of climate on the migration of species – Gradual refrigeration causes species in the northern and southern hemispheres to become distinct – Elevation of temperature the reverse – Effects in the distribution of species which must result from vicissitudes in climate inconsistent with the theory of transmutation
o Chapter 11: Theory of the successive extinction of species consistent with their limited geographical distribution – The discordance in the opinions of botanists respecting the centres from which plants have been diffused may arise from changes in physical geography subsequent to the origin of living species – Whether there are grounds for inferring that the loss from time to time of certain animals and plants is compensated by the introduction of new species? – Whether any evidence of such new creations could be expected within the historical era, even if they had been as frequent as cases of extinction? – The question whether the existing species have been created in succession can only be decided by reference to geological monuments
o Chapter 12: Effects produced by the powers of vitality on the state of the earth's surface – Modifications in physical geography caused by organic beings on dry land inferior to those caused in the subaqueous regions – Why the vegetable soil does not augment in thickness – Organic matter drifted annually to the sea, and buried in subaqueous strata – Loss of nourishment from this source, how supplied – The theory, that vegetation is an antagonist power counterbalancing the degradation caused by running water, untenable – That the igneous causes are the true antagonist powers, and not the action of animal and vegetable life – Conservative influence of vegetation – Its bearing on the theory of the formation of valleys, and on the age of the cones of certain extinct volcanos – Rain diminished by the felling of forests – Distribution of the American forests dependent on the direction of the predominant winds – Influence of man in modifying the physical geography of the globe
o Chapter 13: Effects produced by the action of animal and vegetable life on the material constituents of the earth's crust – Imbedding of organic remains in deposits on emerged land – Growth of Peat – Peat abundant in cold and humid climates – Site of many ancient forests in Europe now occupied by Peat – Recent date of many of these changes – Sources of Bog iron-ore – Preservation of animal substances in Peat – Causes of its antiseptic property – Miring of quadrupeds – Bursting of the Solway Moss – Bones of herbivorous quadrupeds found in Peat – Imbedding of animal remains in Caves and Fissures – Formation of bony breccias – Human bones and pottery intermixed with the remains of extinct quadrupeds in caves in the South of France – Inferences deducible from such associations
o Chapter 14: Imbedding of organic remains in alluvium and the ruins caused by landslips – Effects of sudden inundations – Of landslips – Terrestrial animals most abundantly preserved in alluvium and landslips, where earthquakes prevail – Erroneous theories which may arise from overlooking this circumstance – On the remains of works of art included in alluvial deposits – Imbedding of organic bodies and human remains in blown sand – Temple of Ipsambul on the Nile – Dried carcasses of animals buried in the sands of the African deserts – Towns overwhelmed by sand-floods in England and France – Imbedding of organic bodies and works of art in volcanic formations on the land – Cities and their inhabitants buried by showers of ejected matter – by lava – In tuffs or mud composed of volcanic sand and ashes
o Chapter 15: Imbedding of organic remains in subaqueous deposits – Division of the subject – Phenomena relating to terrestrial animals and plants first considered – Wood sunk to a great depth in the sea instantly impregnated with salt-water – Experiments of Scoresby – Drift timber carried by the Mackenzie into Slave Lake and into the sea – Cause of the abundance of drift timber in this river – Floating trees in the Mississippi – In the Gulf stream – Immense quantity thrown upon the coast of Iceland, Spitzbergen, and Labrador – Imbedding of the remains of insects – Of the remains of reptiles – Why the bones of birds are so rare in subaqueous deposits – Imbedding of terrestrial quadrupeds – Effects of a flood in the Solway Firth – Wild horses annually drowned in the savannahs of South America – Skeletons in recent shell marl – Drifting of mammiferous and other remains by tides and currents
o Chapter 16: Imbedding of the remains of man and his works in subaqueous strata – Drifting of bodies to the sea by river-inundations – Destruction of bridges and houses – Burial of human bodies in the sea – Loss of lives by shipwreck – Circumstances under which human corpses may be preserved under a great thickness of recent deposits – Number of wrecked vessels – Durable character of many of their contents – Examples of fossil skeletons of men – Of fossil canoes, ships, and works of art – Of the chemical changes which certain metallic instruments have undergone after long submergence – Effects of the subsidence of land in imbedding cities and forests in subaqueous strata – Earthquake of Cutch in 1819 – Submarine forests – Berkely's arguments for the recent date of the creation of man – Concluding remarks
o Chapter 17: Imbedding of aquatic species in subaqueous strata – Inhumation of freshwater plants and animals – Shell marl – Fossilized seed-vessels and stems of Chara – Recent deposits in the American lakes – Fresh-water species drifted into seas and estuaries – Lewes levels – Alternations of marine and freshwater strata, how caused – Imbedding of marine plants and animals – Cetacea stranded on our shores – Their remains should be more conspicuous in marine alluvium than the bones of land quadrupeds – Liability of littoral and estuary testacea to be swept into the deep sea – Effects of a storm in the Frith of Forth – Burrowing shells secured from the ordinary action of waves and currents – Living testacea found at considerable depths
o Chapter 18: Formation of coral reefs – They are composed of shells as well as corals – Conversion of a submerged reef into an island – Extent and thickness of coral formations – The Maldiva isles – Growth of coral not rapid – Its geological importance – Circular and oval forms of coral islands – Shape of their lagoons – Causes of their peculiar configuration – Openings into the lagoons – Why the windward side both in islands and submerged reefs is higher than the leeward – Stratification of coral formations – Extent of some reefs in the Pacific – That the subsidence by earthquakes in the Pacific exceeds the elevation due to the same cause – Elizabeth, or Henderson's Island – Coral and shell limestones now in progress, exceed in area any known group of ancient rocks – The theory that all limestone is of animal origin, considered – The hypothesis that the quantity of calcareous matter has been and is still on the increase, controverted
o Description of the Plates and Map
o Index

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Table of Contents:

• Volume 3
o Front Matter
o Chapter 1: Connexion between the subjects treated of in the former parts of this work and those to be discussed in the present volume – Erroneous assumption of the earlier geologists respecting the discordance of the former and actual causes of change – Opposite system of inquiry adopted in this work – Illustrations from the history of the progress of Geology of the respective merits of the two systems – Habit of indulging conjectures respecting irregular and extraordinary agents not yet abandoned – Necessity in the present state of science of prefixing to a work on Geology treatises respecting the changes now in progress in the animate and inanimate world
o Chapter 2: Arrangement of the materials composing the earth's crust – The existing continents chiefly composed of subaqueous deposits – Distinction between sedimentary and volcanic rocks – Between primary, secondary, and tertiary – Origin of the primary – Transition formations – Difference between secondary and tertiary strata – Discovery of tertiary groups of successive periods – Paris basin – London and Hampshire basins – Tertiary strata of Bordeaux, Piedmont, Touraine, &c. – Subapennine beds – English crag – More recent deposits of Sicily, &c.
o Chapter 3: Different circumstances under which the secondary and tertiary formations may have originated – Secondary series formed when the ocean prevailed: Tertiary during the conversion of sea into land, and the growth of a continent – Origin of interruption in the sequence of formations – The areas where new deposits take place are always varying – Causes which occasion this transference of the places of sedimentary deposition – Denudation augments the discordance in age of rocks in contact – Unconformability of overlying formations – In what manner the shifting of the areas of sedimentary deposition may combine with the gradual extinction and introduction of species to produce a series of deposits having distinct mineral and organic characters
o Chapter 4: Chronological relations of mineral masses the first object in geological classification – Superposition, proof of more recent origin – Exceptions in regard to volcanic rocks – Relative age proved by included fragments of older rocks – Proofs of contemporaneous origin derived from mineral characters – Variations to which these characters are liable – Recurrence of distinct rocks at successive periods – Proofs of contemporaneous origin derived from organic remains – Zoological provinces are of limited extent, yet spread over wider areas than homogeneous mineral deposits – Different modes whereby dissimilar mineral masses and distinct groups of species may be proved to have been contemporaneous
o Chapter 5: Classification of tertiary formations in chronological order – Comparative value of different classes of organic remains – Fossil remains of testacea the most important – Necessity of accurately determining species – Tables of shells by M. Deshayes – Four subdivisions of the Tertiary epoch – Recent formations – Newer Pliocene period – Older Pliocene period – Miocene period – Eocene period – The distinct zoological characters of these periods may not imply sudden changes in the animate creation – The recent strata form a common point of departure in distant regions – Numerical proportion of recent species of shells in different tertiary periods – Mammiferous remains of the successive tertiary eras – Synoptical Table of Recent and Tertiary formations
o Chapter 6: Newer Pliocene formations – Reasons for considering in the first place the more modern periods – Geological structure of Sicily – Formations of the Val di Noto of newer Pliocene period – Divisible into three groups – Great limestone – Schistose and arenaceous limestone – Blue marl with shells – Strata subjacent to the above – Volcanic rocks of the Val di Noto – Dikes – Tuffs and Peperinos – Volcanic conglomerates – Proofs of long intervals between volcanic eruptions – Dip and direction of newer Pliocene strata of Sicily
o Chapter 7: Marine and volcanic formations at the base of Etna – Their connexion with the strata of the Val di Noto – Bay of Trezza – Cyclopian isles – Fossil shells of recent species – Basalt and altered rocks in the Isle of Cyclops – Submarine lavas of the bay of Trezza not currents from Etna – Internal structure of the cone of Etna – Val di Calanna – Val del Bove not an ancient crater – Its precipices intersected by countless dikes – Scenery of the Val del Bove – Form, composition, and origin of the dikes – Lavas and breccias intersected by them
o Chapter 8: Speculations on the origin of the Val del Bove on Etna – Subsidences – Antiquity of the cone of Etna – Mode of computing the age of volcanos – Their growth analogous to that of exogenous trees – Period required for the production of the lateral cones of Etna – Whether signs of Diluvial Waves are observable on Etna
o Chapter 9: Origin of the newer Pliocene strata of Sicily – Growth of submarine formations gradual – Rise of the same above the level of the sea probably caused by subterranean lava – Igneous newer Pliocene rocks formed at great depths, exceed in volume the lavas of Etna – Probable structure of these recent subterranean rocks – Changes which they may have superinduced upon strata in contact – Alterations of the surface during and since the emergence of the newer Pliocene strata – Forms of the Sicilian valleys – Sea cliffs – Proofs of successive elevation – Why the valleys in the newer Pliocene districts correspond in form to those in regions of higher antiquity – Migrations of animals and plants since the emergence of the newer Pliocene strata – Some species older than the stations they inhabit – Recapitulation
o Chapter 10: Tertiary formations of Campania – Comparison of the recorded changes in this region with those commemorated by geological monuments – Differences in the composition of Somma and Vesuvius – Dikes of Somma, their origin – Cause of the parallelism of their opposite sides – Why coarser grained in the centre – Minor cones of the Phlegraean Fields – Age of the volcanic and associated rocks of Campania – Organic remains – External configuration of the country, how produced – No signs of diluvial waves – Marine Newer Pliocene strata visible only in countries of earthquakes – Illustrations from Chili – Peru – Parallel roads of Coquirnbo – West-Indian archipelago – Honduras – East-Indian archipelago – Red Sea
o Chapter 11: Newer Pliocene fresh – water formations – Valley of the Elsa – Travertins of Rome – Osseous breccias – Sicily – Caves near Palermo – Extinct animals in newer Pliocene breccias – Fossil bones of Marsupial animals in Australian caves – Formation of osseous breccias in the Mores – Newer Pliocene alluviums – Difference between alluviums and regular subaqueous strata – The former of various ages – Marine alluvium – Grooved surface of rocks – Erratic blocks of the Alps – Theory of deluges caused by paroxysmal elevations untenable – How ice may have contributed to transport large blocks from the Alps – European alluviums chiefly tertiary – Newer Pliocene in Sicily – Loss of the Valley of the Rhine – Its origin – Contains recent shells
o Chapter 12: Geological monuments of the older Pliocene period – Subapennine formations – Opinions of Brocchi – Different groups termed by him Subapennine are not all of the same age – Mineral composition of the Subapennine formations – Marls – Yellow sand and gravel – Subapennine beds how formed – Illustration derived from the Upper Val d'Arno – Organic remains of Subapennine hills – Older Pliocene strata at the base of the Maritime Alps – Genoa – Savona – Albenga – Nice – Conglomerate of Valley of Magnan – Its origin – Tertiary strata at the eastern extremity of the Pyrenees
o Chapter 13: Crag of Norfolk and Suffolk – Shown by its fossil contents to belong to the older Pliocene period – Heterogeneous in its composition – Superincumbent lacustrine deposits – Relative position of the crag – Forms of stratification – Strata composed of groups of oblique layers – Cause of this arrangement – Dislocations in the crag produced by subterranean movements – Protruded masses of chalk – Passage of marine crag into alluvium – Recent shells in a deposit at Sheppey, Ramsgate, and Brighton
o Chapter 14: Volcanic rocks of the older Pliocene period – Italy – Volcanic region of Olot in Catalonia – Its extent and geological structure – Map – Number of cones – Scoriae – Lava currents – Ravines in the latter cut by water – Ancient alluvium underlying lava – Jets of air called 'Bufadors' – Age of the Catalonian volcanos uncertain – Earthquake which destroyed Olot in 1421 – Sardinian volcanos – District of the Eifel and Lower Rhine – Map – Geological structure of the country – Peculiar characteristics of the Eifel volcanos – Lake craters – Trass – Crater of the Roderberg – Age of the Eifel volcanic rocks uncertain – Brown coal formation
o Chapter 15: Miocene period – Marine formations – Faluns of Touraine – Comparison of the Faluns of the Loire and the English Crag – Basin of the Gironde and Landes – Fresh-water limestone of Saucats – Position of the limestone of Blaye – Eocene strata in the Bordeaux basin – Inland cliff near Dax – Strata of Piedmont – Superga – Valley of the Bormida – Molasse of Switzerland – Basin of Vienna – Styria – Hungary – Volhynia and Podolia – Montpellier
o Chapter 16: Miocene alluviums – Auvergne – Mont Perrier – Extinct quadrupeds – Velay – Orleanais – Alluviums contemporaneous with Faluns of Touraine – – Miocene fresh – water formations – Upper Val d'Arno – Extinct mammalia – Coal of Cadibona – Miocene volcanic rocks – Hungary – Transylvania – Styria – Auvergne – Velay
o Chapter 17: Eocene period – Fresh-water formations – Central France – Map – Limagne d'Auvergne – Sandstone and conglomerate – Tertiary Red marl and sandstone like the secondary 'new red sandstone' – Green and white foliated marls – Indusial limestone – Gypseous marls – General arrangement and origin of the Travertin – Fresh-water formation of the Limagne – Puy en Velay – Analogy of the strata to those of Auvergne – Cantal – Resemblance of Aurillac limestone and its flints to our upper chalk – Proofs of the gradual deposition of marl – Concluding remarks
o Chapter 18: Marine formations of the Eocene period – Strata of the Paris basin how far analogous to the lacustrine deposits of Central France – Geographical connexion of the Limagne d'Auvergne and the Paris basin – Chain of lakes in the Eocene period – Classification of groups in the Paris basin – Observations of M. C. Prevost – Sketch of the different subdivisions of the Paris basin – Contemporaneous marine and fresh-water strata – Abundance of Cerithia in the Calcaire grossier – Upper marine formation indicates a subsidence – Part of the Calcaire grossier destroyed when the upper marine strata originated – All the Parisian groups belong to one great epoch – Microscopic shells – Bones of quadrupeds in gypsum – In what manner entombed – Number of species – All extinct – Strata with and without organic remains alternating – Our knowledge of the physical geography, fauna, and flora of the Eocene period considerable – Concluding remarks
o Chapter 19: Volcanic rocks of the Eocene period – Auvergne – Igneous formations associated with lacustrine strata – Hill of Gergovia – Eruptions in Central France at successive periods – Mont Dor an extinct volcano – Velay – Plomb du Cantal – Train of minor volcanos stretching from Auvergne to the Vivarais – Monts Domes – Puy de Côme – Puy Rouge – Ravines excavated through lava – Currents of lava at different heights – Subjacent alluviums of distinct ages – The more modern lavas of Central France may belong to the Miocene period – The integrity of the cones not inconsistent with this opinion – No eruptions during the historical era – Division of volcanos into ante-diluvian and post-diluvian inadmissible – Theories respecting the effects of the Flood considered – Hypothesis of a partial flood – Of a universal deluge – Theory of Dr. Buckland as controverted by Dr. Fleming – Recapitulation
o Chapter 20: Eocene formations, continued – Basin of the Cotentin, or Valognes – Rennes – Basin of Belgium, or the Netherlands – Aix in Provence – Fossil insects – Tertiary strata of England – Basins of London and Hampshire – Different groups – Plastic clay and sand – London clay – Bagshot sand – Fresh-water strata of the Isle of Wight – Palaeotherium and other fossil mammalia of Binstead – English Eocene strata conformable to chalk – Outliers on the elevated parts of the chalk – Inferences drawn from their occurrence – Sketch of a theory of the origin of the English tertiary strata
o Chapter 21: Denudation of secondary strata during the deposition of the English Eocene formations – Valley of the Weald between the North and South Downs – Map – Secondary rocks of the Weald divisible into five groups – North and South Downs – Section across the valley of the Weald – Anticlinal axis – True scale of heights – Rise and denudation of the strata gradual – Chalk escarpments once sea-cliffs – Lower terrace of 'firestone,' how caused – Parallel ridges and valleys formed by harder and softer beds – No ruins of the chalk on the central district of the Weald – Explanation of this phenomenon – Double system of valleys, the longitudinal and the transverse – Transverse how formed – Gorges intersecting the chalk – Lewes Coomb – Transverse valley of the Adur
o Chapter 22: Denudation of the Valley of the Weald, continued – The alternative of the proposition that the chalk of the North and South Downs were once continuous, considered – Dr. Buckland on the Valley of Kingsclere – Rise and denudation of secondary rocks gradual – Concomitant deposition of tertiary strata gradual – Composition of the latter such as would result from the wreck of the secondary rocks – Valleys and furrows on the chalk how caused – Auvergne, the Paris basin, and south-east of England one region of earthquakes during the Eocene period – Why the central parts of the London and Hampshire basins rise nearly as high as the denudation of the Weald -- Effects of protruding force counteracted by the levelling operations of water – Thickness of masses removed from the central ridge of the Weald – Great escarpment of the chalk having a direction north-east and south-west – Curved and vertical strata in the Isle of Wight – These were convulsed after the deposition of the fresh-water beds of Headen Hill – Elevations of land posterior to the crag – Why no Eocene alluviums recognizable – Concluding remarks on the intermittent operations of earthquakes in the south-east of England, and the gradual formation of valleys – Recapitulation
o Chapter 23: Secondary formations – Brief enumeration of the principal groups – No species common to the secondary and tertiary rocks – Chasm between the Eocene and Maestricht beds – Duration of secondary periods – Former continents placed where it is now sea – Secondary fresh-water deposits why rare – Persistency of mineral composition why apparently greatest in older rocks – Supposed universality of red marl formations – Secondary rocks why more consolidated – Why more fractured and disturbed – Secondary volcanic rocks of many different ages
o Chapter 24: On the relative antiquity of different mountain-chains – Theory of M. Elie de Beaumont – His opinions controverted – His method of proving that different chains were raised at distinct periods – His proof that others were contemporaneous – His reasoning why not conclusive – His doctrine of the parallelism of contemporaneous lines of elevation – Objections – Theory of parallelism at variance with geological phenomena as exhibited in Great Britain – Objections of Mr. Conybeare – How far anticlinal lines formed at the same period are parallel – Difficulties in the way of determining the relative age of mountains
o Chapter 25: On the rocks usually termed 'Primary' – Their relation to volcanic and sedimentary formations – The 'primary' class divisible into stratified and unstratified – Unstratified rocks called Plutonic – Granite veins – Their various forms and mineral composition – Proofs of their igneous origin – Granites of the same character produced at successive eras – Some of these newer than certain fossiliferous strata – Difficulty of determining the age of particular granites – Distinction between the volcanic and the plutonic rocks – Trappean rocks not separable from the volcanic – Passage from trap into granite – Theory of the origin of granite at every period from the earliest to the most recent
o Chapter 26: On the stratified rocks usually called 'primary' – Proofs from the disposition of their strata that they were originally deposited from water – Alternation of beds varying in composition and colour – Passage of gneiss into granite – Alteration of sedimentary strata by trappean and granitic dikes – Inference as to the origin of the strata called 'primary' – Conversion of argillaceous into hornblende schist – The term 'Hypogene' proposed as a substitute for primary – 'Metamorphic' for 'stratified primary' rocks – No regular order of succession of hypogene formations – Passage from the metamorphic to the sedimentary strata – Cause of the high relative antiquity of the visible hypogene formations – That antiquity consistent with the hypothesis that they have been produced at each successive period in equal quantities – Great volume of hypogene rocks supposed to have been formed since the Eocene period – Concluding remarks
o Relative Ages of Different Formations
o Deshay's Table of Shells
o General Results
o Fossil Shells Collected by the Author
o Glossary
o Index
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Re: Principles of Geology, by Charles Lyell

Postby admin » Fri Jul 17, 2015 12:08 am

PART 1 OF 3

Introduction
by Martin J. S. Rudwick


CHARLES LYELL'S Principles of Geology is on any reckoning one of the most important books ever published in the earth sciences, and it continues to be significant in modern debates in that field. Furthermore, the concept of "the uniformity of nature" that the Principles embodied and exemplified gave the book a seminal influence on nineteenth-century culture in general, and helped to define what it means to be "scientific."

Among comparable classics, the Principles must be one of the least widely read. There are two simple reasons. The first edition, which is by far the most significant historically, has long been a rarity, and in recent years an increasingly expensive one at that. And the book is very long, and lacks clear internal signposts to the structure of its argument. With this inexpensive reprint edition, the first reason for the neglect of the work will at last disappear; potential readers will no longer need to resort to a rare-book room to read Lyell for themselves. The purpose of this introduction is to alleviate the second problem, by providing an outline of the continuous thread of argument that underlies the 1400-odd pages of the first edition. [1] This is particularly important, because the existence of such an argument has often been overlooked and the work as a whole misinterpreted as a mere textbook or compilation of contemporary knowledge of the science. Furthermore, attention has often been focused on one part of one of the three volumes, a part which was unquestionably of great importance in Charles Darwin's formulation of his theory of evolution. But this exclusive focus has tended to obscure the significance of Lyell's views on species for his own, more strictly geological purposes.

This introduction, then, offers a guide to the structure of the first edition of the Principles. It does not attempt to make any full assessment of the wider significance of Lyell's work, and is designed simply to make it easier for readers to let Lyell speak for himself. First, however, a brief summary of the origins of the book (for further biographical details see Wilson 1972). [2]

THE MAKING OF THE PRINCIPLES

Charles Lyell was born in 1797 into a family of Scottish gentry, but his childhood was spent in the south of England. At Oxford, where he was an undergraduate at Exeter College, his conventional studies were enlivened by William Buckland's celebrated extracurricular course on geology; it was this that first aroused Lyell's serious interest in the science. He then moved to London, and qualified as a barrister at Lincoln's Inn. But he practiced that profession only for a short time, before deciding that his talents as a writer might enable him to earn enough (in addition to a modest income from his father) to devote himself full-time to geology. Briefly he held a part-time position at the newly founded King's College in London, and lectured there on geology; but he resigned on finding that the income it produced did not justify the time it took from his geological research and writing (Rudwick 1975a). He became an increasingly prominent member of the scientific intelligentsia in London, making its Geological Society -- the first of its kind in the world -- his main affiliation (Morrell 1976). In 1823 a visit to Paris, which was then the supreme world center of scientific research, brought him into contact with the leading French geologists. This gave his approach to the science a strongly international dimension, and he was the Geological Society's "Foreign Secretary" during the years when the Principles was being written and published.

While Lyell was in Paris, Constant Prevost showed him the already classic Tertiary strata of the Paris basin, and this experience seems to have turned his attention toward these relatively young rocks. It seems also to have suggested to him that, as Prevost contended against the great comparative anatomist Georges Cuvier, such strata could be interpreted wholly in terms of ordinary geological processes like those in the modern world. Accordingly, one of Lyell's earliest scientific papers, read at the Geological Society in 1825, analyzed some geologically recent lake deposits near his Scottish home and compared them explicitly with some of the much older Parisian rocks. In trying in this way to understand and explain the past as far as possible in terms of the present, Lyell was following a method that was already well established among geologists, including, for example, Buckland (Cannon 1976). Where Lyell began to diverge from them was in the strength of his conviction that this was the only proper method for geology to follow; and that its use should determine what should count as scientific. More specifically, Lyell was profoundly influenced by the greatest contemporary philosopher of science (and practicing scientist) John Herschel, who maintained that only verae causae ("true causes") had any business in a scientific explanation (Laudan 1982, 1987; Ruse 1976). Lyell concurred with Herschel in insisting that the only acceptable causal agents were to be those that could be observed producing the kinds of effect that needed explanation. This stress on the efficacy, indeed the sufficiency, of present and observable "causes" was just one of the several distinct meanings of the "uniformity" that Lyell constantly preached in his geology (Rudwick 1971). It is convenient to distinguish it by the modern analytical term actualism (derived from an older use of "actual," which survives in languages other than English, to denote present events and affairs).

Like Prevost in his criticisms of Cuvier's influential views, Lyell also began to diverge from most other geologists in another way. Cuvier, followed by many others, had claimed that the geological evidence was such that it was necessary to infer that sudden events of great violence -- "catastrophes," as they were commonly termed -- had occurred from time to time in the geological past. In a review of the first volume of the Principles, the Cambridge polymath William Whewell later coined the term catastrophism for this view, and that label will serve here for analytical purposes. Lyell, however, rejected this view altogether, and argued forcefully that "modern causes," acting at their present intensities, were entirely adequate to explain the evidence of the past. Whewell's term uniformitarianism, by which he characterized Lyell's position, needs to be treated with caution, however, because it has been used with many and diverse meanings, both at the time and subsequently.

Lyell's earliest geological writings that gave him scope to discuss such theoretical matters were not papers to the Geological Society, but extended essays for the Quarterly Review, the influential Tory periodical read by the British intelligentsia generally. From these essays it is clear that Lyell's early inclination was to combine his actualism and anticatastrophism with a view of the natural world that was held widely among geologists. This was that the earth's history has been broadly developmental or directional, from distant beginnings -- perhaps as an incandescent globe -- toward its present state, with a correspondingly directional or even "progressive" history of life on earth. It is convenient to use the modern analytical term directionalism to denote this overall interpretation of geology (Rudwick 1971). A directionalist view was quite compatible with Lyell's adoption of an actualistic method, and with his denial of catastrophic events in the past, though it certainly did not entail his approach.

In 1827, however, Lyell's views seem to have undergone a radical change in this last respect. He switched abruptly to a view of the overall pattern of earth history that put him virtually in a minority of one among living geologists. He adopted, and began to refine on the basis of the geology of his own day, the cyclic view of earth history that had been proposed forty years earlier by the Scottish natural philosopher James Hutton. Such a view can be referred to by the modern analytical term steady-state (borrowed, of course, from its use by modern cosmologists). At about the same time Lyell began to make notes that are recognizably the germs of what later became the Principles (Wilson 1972, p.169).

It has been plausibly inferred that Lyell's abrupt theoretical change in geology was related intimately to his experience, at just the same time, of reading the theory of transmutation (in modern terms, of organic evolution) by the aging French naturalist and philosopher Lamarck (Bartholomew 1973, 1976; Corsi 1978). Lamarck's work convinced Lyell that the currently fashionable directionalism in geology would lead inexorably to an out-and-out evolutionism in biology, from which the human species -- body, mind, and all -- could not be excluded. That was a path toward materialism that Lyell had no wish to follow; indeed that he fervently wished to avoid. Whatever his reasons-- and this question remains controversial -- there is no doubt that just as Lyell was planning some kind of major work on geology, he adopted one viewpoint that was highly idiosyncratic, and that his contemporaries found highly implausible, along with others that they were far more ready to consider.

Lyell's book was originally designed to be an elementary work on the lines of Jane Marcet's popular Conversations on Chemistry (1806), and he hoped it might sell widely enough to yield him some useful income. But he soon found his work expanding and deepening into a much more serious and substantial scientific treatise. [3] It should be emphasized, however, that the readers whom Lyell and his publisher hoped the work would attract covered the same wide range as, for example, those of the Quarterly Review. The work was in no way designed just for an audience of "professional scientists" -- that term is in any case anachronistic for the 1830s -- but for the intellectual reading public generally. Lyell's elegant style not only makes the Principles a classic of scientific prose writing; at the time it also made the work widely accessible to a public that found geology an exciting science. [4]

Lyell's ideas, and his store of empirical evidence to support them, were immensely enriched by a long field trip in 1828-29 through France and Italy, initially in the company of another London geologist, Roderick Murchison. [5] After his tour of Sicily, which proved to have been the high point of the whole journey, Lyell summarized his fieldwork in a long letter to Murchison. He described the book he was planning in the following terms:

My work is in part written, and all planned. It will not pretend to give even an abstract of all that is known in geology, but it will endeavour to establish the principle[s] of reasoning in the science; and all my geology will come in as illustration of my views of those principles, and as evidence strengthening the system necessarily arising out of the admission of such principles, which, as you know, are neither more nor less than that no causes whatever have from the earliest time to which we can look back, to the present, ever acted, but those now acting; and that they never acted with different degrees of energy from that which they now exert. (Lyell 1881, vol. 1, p. 234)


This brief passage epitomizes the character of the book that began to appear in public little more than a year later.

First, the title of the work was not chosen casually. In the early nineteenth century any scientific work with the word "principles" in its title still evoked the memory of Isaac Newton's Principia; it was not exactly a modest title for a 32-year-old geologist to propose. For Lyell the word carries that full contemporary meaning; it is not (as in many modern works) a synonym of "textbook." The book is not to be a summary, still less a compilation, of contemporary geological knowledge.

Second, the detailed geology is to be selected for its value in illustrating the use of fundamental "principle[s] of reasoning" in geology. [6] Lyell mentions two distinct principles: the geological "causes" or processes observable at the present day are, he asserts, fully representative of those that have acted in the past, not only in kind but also in degree. Throughout his work, Lyell consistently conflates these two assertions, although to his contemporaries it was clear that the first could be true without entailing the second: it seemed quite conceivable that in the unimaginably long time span of geological history some of the processes known on a small scale within recorded human history might have acted more rarely with paroxysmal or catastrophic intensity.

Third, the two principles are to have a regulative function in the work. It is clear from Lyell's phrasing that they are going to determine what is and what is not admissible in the construction of his geological hypotheses. When the work was published, however, its subtitle embodied the more modest claim that it would merely attempt to explain the phenomena of the past "by reference to causes now in operation." This shows that Lyell was well aware that his disagreement with other geologists was not in fact over the desirability of using the present as a key to the past, but over its adequacy. Lyell's belief in his principles, and his conflation of the two, indicate his commitment to an extreme form of actualism. But this position differed only in degree from that of his scientific opponents.

Fourth, Lyell not only conflates uniformity of kind and uniformity of degree, but also asserts that such uniformity "necessarily" entails a definite "system." The detailed geology in the Principles is to be used not merely to illustrate and justify an extreme form of actualistic method, but also to substantiate a major theoretical framework. The word "system" should be given the full weight of its meaning in early nineteenth-century science: Lyell intends to advocate a theory of the broadest possible scope. Although its nature is not made explicit in this letter, the published Principles shows that Lyell's "system" embodies nothing less than the claim that the overall pattern of earth history has been steady-state or cyclic, and not directional at all. What is significant is that Lyell claimed in his letter that this "system" followed "necessarily" from his two principles. That necessity was far from obvious to other geologists.

The first volume of the Principles was published in the summer of 1830 by John Murray, the leading scientific publisher in London. It was to have been a two-volume work, but it expanded in the writing, and (as explained below) Lyell brought out part of the projected second volume in 1832, and the rest in 1833. The volumes are illustrated with a few expensive copper engravings, some of them handcolored to heighten their geological meaning. In addition, the Principles reflects the beginnings of the routine deployment of wood engravings in book publication; these were much cheaper, and had the added advantage of being printed on the same page as the text to which they referred (Rudwick 1976). Perhaps Lyell himself only realized the potential of such illustrations while he was writing the Principles; certainly their frequency in the text increased more than three times between the first volume and the third (the second volume contains none).

The Principles enjoyed an immediate success with the reading public, and new editions followed in quick succession throughout the decade. Lyell's prose style was found attractive; indeed his critics complained that his style betrayed all too much of his lawyer's training. It presented his theoretical case with a consummate use of rhetoric -- in the proper, nonpejorative sense of that word -- that they found it hard to match. Yet in one respect Lyell made his case less easy to follow than it might have been. Like the seamless web of an advocate's persuasive address to a jury, Lyell's case unfolds from chapter to chapter without interruption. His summaries of the contents of successive chapters, set out in the table of contents in each volume, repay detailed study as a guide to his argument; but the chapters themselves lack attractive or succinct titles. Hence the need for a guide to the structure of Lyell's case.

VOLUME ONE
The Principles of the Principles


The first volume (1830) opens with an introductory chapter (chap. 1) defining the subject matter of geology. Lyell emphasizes its status as an essentially historical science, and its concern with the causes of the processes underlying earth history. This stress on causal analysis is one of the features which sets the Principles apart from much of the geological work of his contemporaries. However, by deliberately rejecting their strongly anti-theoretical approach, Lyell lays himself open to the charge of leading geology back to the bad old days -- as in Lyell's time they were considered to have been -- of the speculative "theories of the earth" of the previous century and earlier. This presents him with a dilemma, for he must somehow disclaim any affinity with most of the earlier system builders, while leaving himself free to acknowledge the value of one in particular, namely Hutton. To Lyell's contemporaries Hutton seemed as deplorably speculative as any other system builder. Yet Hutton's theory, epitomized by its conclusion that in studying the earth "we find no vestige of a beginning, no prospect of an end," was the one that Lyell proposed to revive and refine. He therefore tries to forestall the criticism that his own system too is merely speculative, by emphasizing that geology must not be confused with "cosmogony." In other words, geology must exclude speculations about the origin of the earth, and confine itself to an analysis of the subsequent changes that the earth has undergone. Hutton, Lyell maintains, was the first to realize this, and his view "will ultimately prevail" (p. 4). Thus right at the outset Lyell proclaims his Huttonian intentions quite explicitly.

These remarks lead at once into the first major section of the Principles, a review of the history of geology from antiquity to the early years of the nineteenth century (chaps. II-IV). Much of the detail is borrowed, with scant acknowledgment, from the historical essay in Giovanni Battista Brocchi's already classic monograph (1814) on the Tertiary mollusks of the Sub-Appenine Hills in northern Italy McCartney 1976). The aim of this section, however, is not really to provide historical background but to argue a case as persuasively as possible. This so-called history of geology is a highly polemical tract for the times; to treat it as straight history would be to ignore the contemporary situation to which the book is addressed (Porter 1976). Indeed, Lyell admitted privately that the historical form was merely a discreet disguise, and that he would have liked to extend the account to include living authors, in order to make the attack more pointed still (Lyell 1881, vol. 1, p. 271; Porter 1982). Like many would-be reformers, Lyell rewrites history in order to demonstrate that those whose present views he is attacking are inheritors of a historical tradition that has had a retarding influence on the progress of the science. He contrasts this with the more enlightened tradition in which he finds his own antecedents, though in fact he spreads his praise thinly, and thereby accentuates his own innovative originality.

The tradition he is attacking has, he implies, several related characteristics. It tends to use Scripture to support or contribute evidence for geological theories; it tries to use the phenomena of geology to infer the origin of the earth; it views the history of the earth as a series of highly dramatic or extraordinary events; and it is reluctant to accept an indefinitely long time scale. By contrast, the approach that Lyell intends to advocate makes a sharp disjunction between geological research and the interpretation of Scripture; it eschews all cosmogonic ambitions of reaching back to the origin of the earth; it interprets the past history of the earth as a series of events comparable to those still occurring; and it readily accepts a vast time scale for earth history.

Lyell's polemical interpretation of the history of geology naturally entails distortion and oversimplification of the theories of his predecessors (Ospovat 1976). But from his point of view it has the advantage of tarring with the same brush the popular but scientifically worthless speculations of the "Mosaic" [7] or "Scriptural" geologists of his own time; the far more respectable catastrophism of his former teacher Buckland, with its relatively liberal interpretation of Scripture; and the still more empiricist catastrophism of geologists such as Buckland's Cambridge counterpart, Adam Sedgwick. From its original conception as a popular work, the Principles had retained the function of combating those who were misleading the general public into believing that a literal interpretation of the Creation narrative in Genesis was still tenable. Most other geologists, whether or not they agreed with Lyell on specific issues, would in fact have considered themselves his allies in hoping "to free the science from Moses" (Lyell 1881, vol. 1, p. 268). But Lyell implies that there is an inherent affinity between catastrophist and Mosaic geology, and that this illustrates the grave dangers of slipping in any degree from his own highly restrictive conception of "uniformity."

The importance of Lyell's "history" in the strategy of the whole work becomes clearer in the following chapter (chap. V), which summarizes the lessons to be learned from it. Here he maintains that the slowly increasing reliance on ordinary secondary causes in geology has been similar to the growth of the scientific attitude as a whole; to be Lyellian in geology is, in effect, to be scientific. But he argues that the greatest single factor retarding the progress of geology has been an inadequate conception of the time scale of earth history. Using a favorite tactical device of an analogy with human history (Rudwick 1977), he shows how this inevitably telescopes events together, giving an illusion of swift and extraordinary happenings and astonishing coincidences. It was this, he suggests, that made geologists unwilling to believe in "uniformity" and led them to expect discontinuity between past and present unless the evidence to the contrary was overwhelming. Lyell maintains, however, that the vast time scale which the Huttonian system demanded is now being vindicated by the discovery of more and more strata that need to be intercalated into the succession previously known. Citing his own observations in Sicily, he argues that as a result of this implicit expansion of the time scale it is no longer necessary to postulate causes exceeding in intensity those now in operation; or -- showing a significant elasticity in his conception of uniformity -- those that might conceivably occur in the future. This qualification indicates again that Lyell is not concerned merely to advocate actualism as a method, but to argue for a steady-state or cyclic system in which geological processes are not, as the directionalists suggested, tending toward a state of quiescence.

In placing such emphasis on the sense of the geological time scale, Lyell shows a penetrating awareness of the nature of his task of persuasion. For although his scientific colleagues (unlike the Mosaic pseudogeologists) readily accepted a vast time scale on the intellectual level, Lyell recognized that it was their scientific imagination that needed transforming. Much of the detailed argument of the Principles is therefore designed to draw out the full implications of a belief which they already claimed to hold.

Although a vast time scale is now more generally conceded, Lyell maintains, other habits of mind still continue to retard geology. Of these the most important is a failure to recognize the distorting effect of our viewpoint as subaerial terrestrial beings. This causes us to underestimate the magnitude of submarine and subterranean geological processes. An intelligent aquatic being and a "gnome" confined to subterranean regions would form very different but equally distorted views on geology. Geologists must therefore at least make "an effort both of the reason and the imagination" to allow for the effects of this limitation (p. 81). As with regard to time, here too it is a conversion of the imagination that is needed, if geologists are to gain a true perspective on the problems of earth history. But this argument has a further significance for Lyell. He suggests that it is our naturally biased viewpoint which has led to an overemphasis on the destructive or "wasting" aspects of geological processes and to a corresponding underemphasis on the renovating or formative aspects. By deliberately seeking to correct this natural bias, Lyell can argue that the destructive and formative agencies are in fact in balance. He can thereby maintain that the earth as a whole remains in a steady-state condition. This whole discussion illustrates clearly how Lyell's approach, far from being simply empiricist, embodies a more sophisticated understanding of the role of interpretation in geology than that of many of his contemporaries (Rudwick 1977; Gould 1987, chap. 4).

After some further scathing remarks about those who consider themselves "at liberty to disregard all modern analogy," he leaves what he terms rhetorically the "exploded errors" of the catastrophists, and opens his attack on the "weightier objections" of the directionalists (p. 91). This attack (chaps. VI-IX) would have been placed more logically in a later part of the work, where the actual evidence of the rocks could have been tested against both a steady-state and a directionalist view of earth history. But Lyell seems to have felt that the scientific authority and popularity of the directionalist view were so great that confidence in it had to be undermined at the outset: only if his readers are first prepared to believe that directionalism involves highly uncertain inferences from the available evidence will they give a fair hearing to his alternative interpretation.

Two areas of evidence were widely held to favor a directionalist model of earth history, and Lyell criticizes each in turn. The first is the evidence of directional climatic change in the past history of the earth. In particular, the fossils of the Secondary strata [8] of Europe were considered to be most closely analogous to the animals and plants now living in tropical regions. This seemed good evidence in support of Leibniz's and Buffon's earlier theory of the gradual cooling of the earth. This had recently been revived in popularity under the scientific authority of Joseph Fourier's work on heat flow and Louis Cordier's calculations from the geothermal gradient; it also seemed to fit well with the "nebular hypothesis" of the origin of the solar system (Rudwick 1971; Lawrence 1977; Brush 1987). lf the earth had had a hot or incandescent origin and had been losing heat continuously by radiation, the climate in any given latitude should show evidence of directional change.

Lyell admitted that his theoretical preconceptions had led him initially to doubt the validity of this evidence, but he claimed that his own experience had forced him to accept it. To the Scottish naturalist John Fleming -- who was perhaps even more ardently "uniformitarian" than Lyell himself -- he wrote: "As a staunch advocate of absolute uniformity in the order of Nature, I have tried in all my travels to persuade myself that the evidence was inconclusive, but in vain" (Lyell 1881, vol. 1, p. 260). Indeed it was on his own travels that he had found what he believed to be a "crucial experiment" proving the reality of climatic change (chap. VI). It was always possible to argue, as Fleming did, that the tropical appearance of the more ancient faunas and floras was illusory: they were merely analogous to present tropical organisms, and since they did not belong to living species, it was impossible to prove that their ecological preferences had really been tropical. Lyell explains, however, that the geologically young strata he had explored in Sicily contain mollusks of extant species which are consistently larger than their living representatives, and he claims this as conclusive evidence that the climate was somewhat warmer in the Mediterranean in geologically recent times. By analogy, therefore, the evidence of older periods should also be accepted as valid.

But this does not lead Lyell to accept the usual directionalist interpretation of that evidence. A gradually decreasing temperature in Europe during the Tertiary period has somehow to be "reconciled with the existing order of nature," or in other words with the "absolute uniformity" of a steady-state interpretation of earth history (p. 104). This reconciliation is effected by means of what, in a letter to the Sussex geologist Gideon Mantell, he had called "my grand new theory of climate" (Lyell 1881, vol. 1, p. 262). This is a hypothesis of continual climatic fluctuation around a mean, which can account for any degree of local climatic change "easily and naturally," without recourse to any sudden or directional changes on a global scale (chap. VII). Drawing on published accounts of the physical geography of many different regions, especially on recent explorations of the polar regions, and applying Alexander Humboldt's concept of isothermal lines, he argues that local climate is not a simple function of latitude. It is also greatly influenced by the distribution of land and sea, the direction of winds and currents, and other similar factors: "Latitude is one only of many powerful causes, which determine the climate of particular regions of the globe." Hence, if -- as he would argue later in the work -- there has been a round of ceaseless change in the distribution of land and sea, "there must be a never ending fluctuation in the mean temperature in every zone" (p. 111).

More specifically, Lyell conjectures that major changes in the distribution of continents and oceans could have been such as to generate a global climatic cycle of vast duration. Reviving a notion that goes back to Antiquity, he suggests that the global climate might oscillate between what he terms metaphorically the "winter" and "summer" of the "great year." This highly speculative notion neatly allows him to accept the evidence for a general cooling trend through out the clearly recorded periods of earth history (extending at this time from the Carboniferous to the present), but to interpret it not as a once-for-all directional cooling from a primitively hot globe, but as just one part of an immensely long cycle that could well be reversed and repeated in the future. This leads him to a claim that was as startling to his contemporaries as it may be to modern readers. Given the cyclicity that he postulates, Lyell conjectures that "the huge iguanodon might [in future] reappear in the [English] woods, and the ichthyosaur in the sea, while the pterodactyle might flit again through umbrageous groves of tree ferns" (p. 123). No passage shows more clearly how Lyell intended his system to be not merely steady-state, but -- if the evidence demanded it -- vastly cyclic (Ospovat 1977; Gould 1987). [9]

This climatic hypothesis is next tested against the actual evidence of past climatic change (chap. VIII). Lyell takes the tropical aspect of the Carboniferous period as an example, and argues, like the Parisian paleobotanist Adolphe Brongniart, that the strata and their fossils indicate a predominately marine environment with scattered islands. But unlike Brongniart he uses this reconstruction to show that on his theory a climate warmer than that now found in Europe would follow naturally, and that there is no reason to attribute it to a greater degree of "central heat." Having thus rejected the directionalist interpretation of climatic change, Lyell then attacks the allegedly sudden (that is, catastrophist) nature of the successive changes. He argues that, as in other phenomena, the appearance of sudden change merely reflects the incompleteness of our evidence. If all the successive stages were preserved, the changes would be seen to have been gradual. Lyell concludes that the evidence of climatic change does not support the theory of a directional cooling of the globe; instead it supports his own theory of continual fluctuation around a mean. He suggests that while his theory needs further refinement, it is "more consistent with philosophical caution" to adopt a steady-state explanation as a working hypothesis, rather than a theory of directional change (p. 142). Once again, to be Lyellian is to be scientific.

Having explained away the climatic evidence, Lyell turns to a brief attack on the other main directionalist argument, that of "progress" in organic life (chap. IX). That he deals with this organic aspect only after an extended critique of the inorganic (i.e., climatic) aspect should serve to emphasize that the directionalist system he is attacking was not a purely biological theory: "progressive" biological changes (i.e., the appearance of successively "higher" forms of life) were regarded as having occurred in step with similarly directional changes in the inorganic environment. Once again he correlates the establishment of a steady-state interpretation with the actualistic belief that past events were "governed by the laws now in operation" (p. 144). Since no well-defined faunal succession was known in 1830 for periods before the Carboniferous, Lyell has no great difficulty in arguing here that the apparent progress in the rank of organic life is an illusion, owing simply to the differentially selective preservation of terrestrial and aquatic animals. Thus he argues, for example, that mammalian remains are absent in earlier strata, not because mammals had not yet come into existence, but because most of them are terrestrial and therefore unlikely to be preserved in sediments that are predominately marine in origin.

On the other hand, Lyell does not apply the same reasoning to man himself. Man is the great exception. Lyell accepts at its face value the positive evidence that man appeared on the earth in geologically recent times. But he argues that this is no evidence for "a progressive system" (p. 155). Lyell maintains this inconsistent position because he makes a sharp separation between man's physical and mental characteristics: man's evident superiority is due to his power of reason, particularly his power of improvable reason, which is precisely the feature that distinguishes him clearly from other animals. Hence on the physical level his appearance denotes no special progress in the organic world -- man is just another mammalian species -- while on the "moral" level his appearance is a phenomenon of an entirely different kind (pp. 156, 163). All the same, Lyell has to admit that man's rational powers do in fact enable him to exercise an important influence on his physical environment. This might have been held to invalidate the actualistic use of the present as a reliable key to the more ancient, prehuman periods of earth history. To forestall this criticism, Lyell is therefore obliged to argue that the physical effects which man has produced on the earth's surface are limited and localized in character, and strictly analogous to those that any animal species with new habits might have produced in the past.
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Re: Principles of Geology, by Charles Lyell

Postby admin » Fri Jul 17, 2015 12:09 am

PART 2 OF 3

Present Inorganic Processes

This concludes Lyell's preliminary lines of attack -- on Mosaic geology and on the catastrophism and directionalism of his scientific opponents -- and it clears the ground for the presentation of his own system. The rest of the first volume and the whole of the second are devoted to a description and analysis of geological processes now in operation. This is designed primarily to demonstrate that these processes, operating at their present intensity, are completely adequate to explain all the phenomena of the past. Three categories of processes are considered in turn: the inorganic, the organic, and those involving an interaction between the two.

Inorganic processes are divided for convenience into the aqueous and the igneous. This reflects the general recognition, which had emerged from the inconclusive earlier debate between Neptunists and Vulcanists, that both classes of process are in fact important. Unlike Hutton, however, Lyell emphasizes that both aqueous and igneous processes "are instruments of decay as well as reproduction" (p. 167). In other words, each contributes to both sides of the balance of forces that maintains the earth in a steady-state condition. This belief is reflected in Lyell's classification of aqueous processes. He considers first the action of running water, but divides this into two parts: its action in erosion (chaps. XXII) and in deposition (chaps. XIII-XIV). His consideration of marine currents and tides is similarly divided into a section on their power of erosion (chaps. XV-XVI) followed by one on their power of deposition (chap. XVII).

These chapters need not be analyzed in detail. Like the rest of the Principles they show impressive power in the marshaling of evidence from many published sources, particularly from the massive catalogue (1822-24) of the effects of "modern causes" compiled by the Gotha geologist (and diplomat) Karl von Hoff, as well as from Lyell's own observations in France and Italy. [10] They are also interspersed with many barbed comments on the illogicality of "some theorists" in assuming that it is necessary to postulate past processes more drastic than those that are still in operation. Throughout the argument the emphasis is on the magnitude of the effects which these present processes can achieve, even at their present level of intensity and even within the geologically short period of recorded human history. The implication is clear: given the immensity of the geological time scale and the fragmentary nature of our evidence of past periods, these same processes at their present intensity are quite adequate to explain everything that geology describes. This emphasis on the magnitude of present processes shows that Lyell has no commitment to the slowness or gradualness of geological change (that is, to gradualism) for its own sake. On the contrary, the more catastrophist he can be -- within the strict limits allowed by his version of actualistic method -- the more easily he can persuade his readers to accept a steady-state system in which the past has been no more catastrophic -- but also no less -- than the present.

Lyell's survey of igneous processes follows similar lines. It too is divided into two main parts, dealing with volcanic and seismic phenomena. As in previous sections he is concerned above all to emphasize the magnitude of these effects, explicitly in order to undermine the credibility of the directionalist belief that they are now far less intense than they were in the geological past. On his usual policy of proceeding from the known to the unknown, he gives special prominence in the section on vulcanism (chaps. XVIII-XXII) to the exceptionally well recorded volcanic history of Vesuvius and Etna, both of which he had studied at first hand in 1828. If there were no human records to date the various eruptions, Lyell argues, it would be easy to conclude that they all occurred during a single disastrously catastrophic episode. Yet in fact these very regions had been some of the most attractive habitable areas in the Mediterranean world throughout recorded history, in spite of sporadic eruptions. This demonstrates how, even within this geologically short span of time, false conclusions about the past inevitably result from telescoping events that were in fact far apart in date. Lyell also shows how the most recent eruptions have been no different in kind or scale from the most ancient; no dividing line can be drawn there between past and present. This point is stressed particularly in his description of the volcanoes of the Canary Islands, in order to refute the influential "elevation crater" theory of the great Prussian geologist Leopold von Buch; Lyell argues that here too there is no evidence of any former processes different in kind or even in degree from those that have been observed in operation.

The description of earthquakes and their effects (chaps. XXIII-XXVI) likewise gives greatest prominence to the most authentically documented cases, such as the great Calabrian earthquake of 1783. Lyell is chiefly concerned here to show the magnitude of the permanent physical effects of earthquakes, especially in altering the level of large tracts of land. But these physical effects of earthquakes (as opposed to their destructive effects on human life) have been recorded most fully in the more recent periods of history; and Lyell therefore arranges his catalogue of earthquakes in reverse chronological order, backward from the most recent. In particular, he gives a detailed analysis of the controversial phenomena of the so-called Temple of Serapis at Pozzuoli near Naples. He argues that these ruined columns, which halfway up are full of the borings of marine organisms, demonstrate elegantly that the land at this point has undoubtedly suffered both depression and later elevation since classical times. Lyell's choice of a picture of the Temple of Serapis as the frontispiece for the first volume undoubtedly surprised his readers, who expected books on geology to have as their visual summary some landscape or picture of strata, not an antiquarian monument. But in fact Lyell's choice was highly appropriate. The Temple of Serapis epitomizes perfectly his argument that ceaseless nondirectional fluctuations of physical geography have been going on even in historic times, caused not only by superficial aqueous processes but also by deep-seated igneous processes. [11]

Yet it is significant that when Lyell is faced with an example of modern elevation that has not been accompanied by earthquakes, he refuses to accept its reality at all. He ridicules von Buch's "extraordinary notion" that the land around the Baltic is "slowly and insensibly rising," although there are exceptionally careful historic records available to support it. He is unable to accept the fact of elevation, despite its impeccable actualism and extreme gradualism, because it cannot be reconciled with his own (more catastrophic!) theory of elevation by earthquakes (pp. 227-32). [12]

Lyell includes these tectonic phenomena of elevation and depression, along with the volcanic, under the general heading of igneous processes,. because he follows the Huttonian view that there is a close causal relation between them: earthquakes and volcanic eruptions are essentially alternative manifestations of the same processes of magmatic intrusion and expansion occurring at great depths. This, Lyell suggests, is supported by the close spatial connection between volcanic and seismic areas, and it accounts for the fact that earthquakes, like volcanoes, commonly affect the same region again and again. Hence the time required for successive lava flows to build up a large volcanic cone could also be time enough for successive earthquakes to convert an area of sea into a range of hills. It is at this point that Lyell's emphasis on the connection between earthquakes and the elevation or depression of land emerges overtly as an essential part of his strategy. If he can persuade his readers that even the earthquakes of historic times have effected permanent changes in the level of the land, he can argue that similar earthquakes throughout geological time are sufficient to explain the elevation of even the greatest mountain ranges, thereby eliminating the need to postulate more intense or sudden earth movements in the past.

Lyell concludes his review of these processes by claiming that "the renovating as well as the destroying causes are unceasingly at work, the repair of the land being as constant as its decay" (p. 473). He senses, however, that there is a possible flaw in this system of perfectly balanced forces. He argues that if seismic movements of elevation and depression were exactly matched, the net effect of all igneous processes would be unbalanced, because volcanic processes -- unlike earthquakes, which both elevate and depress -- tend only to increase the inequalities, building up volcanic cones and lava flows on the surface. In order to maintain the stability and balance of the system he is therefore obliged to argue, in an unusually tortuous piece of reasoning, that the total amount of seismic subsidence must exceed the total amount of elevation. It is on this highly speculative note that he concludes his interpretation of inorganic geological processes. In a passage that recalls the more explicit providentialism of Hutton, he claims that the humanly destructive agency of earthquakes is necessary for the maintenance of a balance between land and sea, and hence for "the subserviency of our planet to the support of terrestrial as well as aquatic species." Above all other processes, it is "essential to the stability of the system" (p. 479).

The argument of the whole volume is summarized by that concluding phrase. Lyell has now interpreted the whole range of inorganic geological processes in such a way as to demonstrate that the physical features of the earth are in a state of perpetual flux. But this principle of change consists of endless fluctuation around a stable mean, not of overall directional alteration. Erosion is balanced by deposition, seismic subsidence by seismic elevation and vulcanism. The details of geography change continually, and with them the pattern of local climate; but the overall nature of the globe remains constant.

VOLUME TWO
Present Organic Processes


As foreshadowed in the concluding remarks of the first volume, the second (1832) continues the argument on the same lines but deals with organic processes. Because of its subsequent impact on Charles Darwin, the first part of this volume, which deals with the nature and history of organic species, is probably the most widely known section of the Principles. Yet in Lyell's own scheme it is not a purely biological digression or parenthesis; it is an essential part of his geological argument. Lyell had originally intended to publish the whole work in two volumes, and it was only at a late stage that he decided to publish separately the first half of the projected second volume, in order to avoid the delay which the completion of the later sections -- which became the third volume -- would involve (Lyell 1881, vol. 1, p. 355). He therefore stated clearly in the preface of this truncated second volume that its contents would "be found absolutely essential to the understanding of the theories hereafter to be proposed." The argument of the second volume can only be understood fully in the light of the third and final volume.

Lyell opens his argument by claiming that all questions about the history of life -- its progressive development or uniform maintenance as part of a stable system -- must be related ultimately to the question of changes at the level of species. As with inorganic processes, large-scale features are to be understood in terms of the summation of small-scale events. Therefore, the first topic to be discussed is the objective reality of the species as a basic unit of biological description (chaps. I-IV). It was just this reality that was increasingly in doubt as a result of the growing influence -- especially but not only among French naturalists -- of Lamarck's earlier theory of transmutation (Corsi 1978). Lyell therefore feels bound to discuss Lamarck's theory at length in the Principles. His private reason for opposing transmutation -- his concern that it threatens the "dignity of man" -- is unacknowledged; as always with Lyell, the private realm remains very private indeed (porter 1982). His explicit reason is strictly scientific: he points out that the acceptance of Lamarckian transmutation would have even more profoundly unsettling implications for the work of geologists than it would for biologists. The latter, studying organisms only at one point in geological time, can always proceed for taxonomic purposes as if the species they describe have permanent reality. But if all organic forms are in a state of flux, geologists cannot be certain what they are describing.

Lyell admits that Lamarck's theory has had the attraction of avoiding "the repeated intervention of a First Cause," i.e., an act of creation by divine agency, for every new species (p. 18). But he throws serious doubt on its validity. Lamarck's views on the vast scale of geological time would have been highly attractive to Lyell, but on the question of transmutation it was Lamarck's opponent Cuvier whom Lyell chose to follow. Cuvier's immense scientific authority had lent prestige to catastrophist theories in geology, but he had argued for sudden revolutions precisely because he believed that present "causes" were inadequate to explain the phenomena of geology. Similarly he had argued against transmutation on the grounds that it was unsupported by actualistic evidence, in particular by the crucial evidence of the mummified animals found in Egypt. So Lyell, whatever his private reasons for opposing Lamarck, can claim openly that he is bound by his methodology to reject it. He concludes, like Cuvier, that if no transmutation can be seen to have occurred during the largest available time span of recorded human history, there is no warrant for assuming that the still longer periods of geological time would have had any greater effect. To argue otherwise would be to invert the principle of actualism that he had employed so effectively in his analysis of inorganic processes. Of course, Lyell accepts the variability of species, but -- like Cuvier again -- he argues that there are definite limits to the degree to which individuals can vary from their parent type, whether under human domestication, hybridization, or ecological changes in the wild. There is no evidence for the "indefinite capacity of varying from the original type" which would be required for transmutation. Lyell concludes that "species have a real existence in nature," each being adapted permanently to a particular mode of life (p. 65). The units described by the paleontologist in studying the faunas. and floras of ancient strata are therefore not figments of the imagination.

Having established that species are natural units, Lyell turns next to the question of their present geographical distribution and the processes that may account for it (chaps. V-VII). Like the previous topic, this is introduced explicitly for its geological importance. Although adaptation is universal, it cannot by itself explain the facts of biogeography: similar ecological habitats are occupied by different organisms in different faunal and floral provinces (Browne 1983). In order to understand the reasons for the existence of such provinces it is first necessary to consider the means available to species to alter their geographical ranges in the course of time. Some such changes are possible even without any alterations of physical geography. All species have various means of dispersal by which they may spread to new areas, and Lyell reviews the means available to different groups of organisms (including man, who forms no exception in this respect). He emphasizes that even the most improbable or rarely occurring means may become important in the long span of geological time.

But the principle of change introduced by this discussion now raises the wider problem of changes in the specific composition of faunas and floras, or in other words the processes that may be responsible for the introduction and elimination of species (chaps. VIII-Xl). Lyell's description of the means of geographical dispersal of species leads to the question of the spatio-temporal points of origin from which species may have been dispersed. He deals only briefly with the question of the origin of species, proposing a bare working hypothesis for the circumstances under which new species may be introduced, without discussing the means. His hypothesis is simply that each species has come into existence at a single point in space and time (that is, that species are monogenetic), conditions at that point being suitable for it to exist and survive for some period of time. Lyell suggests that the observed patterns of distribution of species are consistent with the assumption that species have in the course of time spread from such unique points of origin. He implies that these points are distributed "uniformly" in space and time, arguing that faunas and floras of high endemicity do not support the idea of special localized "centres or foci of creation" at which "the creative energy has been in greater action than in others" (p. 126).

In this discussion Lyell, like his contemporaries, uses the language of "creation" freely and even casually. He later said he had left it to be inferred that he believed in the origin of species by some unknown but natural or "secondary" cause (Lyell 1881, vol. I, p. 467). But he would not have regarded that as incompatible with his highly providentialist sense that new species have always appeared at adaptively appropriate points in space and time. In fact, however, Lyell can afford to express himself vaguely on this vexed question, because the precise mode of origin of species is peripheral to his main geological argument. What matters to him is simply to establish that new species appear on the scene one by one -- by whatever means -- suitably adapted to the ecology of the habitat in which they are to live. By implication this process not only occurs at points uniformly distributed in space and time, but also without any inherent directional tendency: new species are not of higher rank than earlier ones. Any process that involved adaptive improvement, however slight or gradual, would have undermined Lyell's fundamental opposition to all directionalist interpretations of the history of life.

The origin of species is introduced at this stage, however, only to open a discussion of the processes which regulate the continued existence and survival of species after their original appearance. Lyell describes the ecological checks and balances between different organisms, which tend to maintain the stability of organic communities. But this stability is perpetually threatened from two directions. The chance dispersal of a single species to a new area, even without any change in physical geography, can have drastic effects on the communities into which it is introduced, for example if it is a predator against which the established species have no defense. In addition, the ceaseless changes in physical geography (analyzed in the first volume) must always tend to increase the probability of such radical ecological effects, often eliminating the physical or biotic environment on which particular species depend for their survival. Moreover, even relatively minor and gradual physical changes may occasionally have sudden and drastic effects, for example with the final submergence of a narrow isthmus or the flooding of a continental area depressed below sea level. (This is another point at which Lyell is able to provide for relatively catastrophic effects within an actualistic framework.) He therefore concludes that an incessantly fluctuating physical geography implies an equally incessant process of extinction: "Amidst the vicissitudes of the earth's surface, species cannot be immortal, but must perish one after the other, like the individuals which compose them" (p. 169). Even Lamarck's theory offers no escape from this conclusion, he maintains, because in changing physical circumstances a previously well-adapted species would be eliminated by competition from other species better adapted to the new conditions, long before it could be transmuted by the imperceptibly slow process that Lamarck had postulated.

If the successive extinction of species is thus "part of the constant and regular course of nature," it is necessary to consider next "whether there are any means provided for the repair of those losses" (p. 179). If Lyell is to show that the organic world, like the inorganic, is part of an overall steady-state system, he must at least establish the possibility that the production of new species is as constant and regular a process as their extinction. Yet he is on difficult ground at this point, because he cannot produce any positive evidence for species production as a "cause now in operation," and he is forced to explain why "so astonishing a phenomenon can escape the attention of naturalists" (p. 179). He overcomes this difficulty by assuming that species production, like extinction, is an event that is distributed uniformly in space and time; hence he argues that it would be extremely unlikely that any single instance would have been accessible to scientific observation within the span of modern human history. At this point, then, Lyell has to admit that the method of actualism fails and must indeed be inverted. The present must here be interpreted in the light of the past; that is, by the geological evidence that new species have been introduced -- by whatever means -- in replacement of those that have become extinct. Whatever mechanism (if any) he had in mind, his argument implies that species production is a relatively sudden event. But this is no more substantial a concession to catastrophism than is his use of sudden earthquakes as the agent of elevation. In both cases large results (the appearance of a new fauna; the elevation of a mountain range) are produced by the summation of piecemeal occurrences of small-scale events, spread over a long period of time.

In spite of this weak evidence on the origin of species, the reader is left in no doubt about Lyell's broader views. The organic world, like the inorganic on which it depends, is subject to perpetual flux, yet without any directional change in its overall character. Species, the adaptively stable units of the organic world, come somehow into existence at ecologically appropriate but broadly distributed points in space and time; they survive for a longer or shorter period of time, in dynamic ecological equilibrium with other organisms, spreading more or less widely; but sooner or later they are eliminated by the pressures of the ever-changing physical and biotic environment. The production and extinction of species are thus processes that are as ceaselessly in operation, and as perpetually in balance, as the inorganic processes of deposition and erosion, elevation and depression. The organic world, like the inorganic, is part of a stable system.

Organic/Inorganic Interactions

Having concluded his analysis of organic processes "now in operation," Lyell devotes the rest of the second volume to a discussion of the ways in which the organic world affects the inorganic. The first section (chap. XII) is in the nature of a parenthesis, being a further attack on certain directionalist interpretations. In particular, Lyell is concerned here to reiterate that the continual destruction of land areas by erosion is balanced by the igneous processes of elevation and vulcanism, and not, as Sedgwick had recently suggested, by the organic processes of soil formation. Soil is indeed to some extent a "conservative" agent, reducing the rate at which erosion would otherwise operate; but Lyell emphasizes that it is in no sense an "equipoise" to erosion. It is to igneous forces that Sedgwick should look, for assurance that erosion is indeed counteracted, so that habitable dry land is -- providentially -- a permanent feature of the globe.

Lyell's main discussion of the effects of organisms on the inorganic world is in reality an analysis of the circumstances under which organisms are likely to be preserved as fossils (chaps. XIII-XVII). The importance of this section does not emerge clearly until the third and final volume. Like the rest of his analysis of causes now in operation, it is an essential part of Lyell's program for the reconstruction of the past history of the earth. The evidence of the fossil record cannot be used as a reliable guide to the history of the organic world without a correct understanding of the complex relation between living organic communities and the fragmentary record that they may leave in the fossil state.

Lyell treats this topic systematically, considering first the preservation of terrestrial organisms in terrestrial deposits such as peat, alluvium, volcanic tuffs, and cave deposits (chaps. XIII-XIV). He throws doubt on the alleged occurrences of fossil man, questioning -- like Cuvier and Buckland before him--the contemporaneity of man and the large extinct mammals (Grayson 1983). But he also criticizes the assumption of Buckland and others that a single catastrophic "diluvial" episode might have been responsible for a variety of alluvial and cave deposits. He next considers the preservation of terrestrial organisms in the much more widespread deposits of lakes and seas (chaps. XV, XVI). Here he emphasizes the "accidental and partial" circumstances which determine whether or not a particular terrestrial species is preserved. He points out that in consequence fossil assemblages of terrestrial organisms can never be reliable indicators of the real specific diversity that existed at earlier periods in earth history. This conclusion is explicitly produced to refute the directionalist inference that organic communities were less diverse in earlier periods. (Lyell argues that man, on the other hand, is in principle extremely likely to be preserved in the fossil record by reason of his widespread movements and activities on land and at sea; the absence of any actual traces of man, except in extremely recent deposits, is therefore evidence for the genuinely recent origin of the human species.) Third, Lyell turns to the chances of preservation of aquatic species in lacustrine and marine deposits (chap. XVII). In contrast to the previous sections, the emphasis here is on the high chances of preservation of those organisms -- especially marine mollusks -- that have hard skeletal parts. The implication, to be drawn out fully in the third volume, is that the fossil assemblages of these organisms provide the most representative sample of the organic world of former periods.

The second volume ends with a brief discussion of coral reefs and limestones (chap. XVIII). Lyell interprets the sub-circular form of coral atolls as a reflection of their foundation on the rims of submerged volcanic craters. [13] He uses their distribution as an argument in favor of his earlier speculation that seismic subsidence exceeds elevation in total amount, thereby ensuring the dynamic stability of the physical geography of the globe. He also argues against the directionalist belief that because limestones are more abundant in later than in earlier strata, there must have been a progressive increase in the abundance of lime-secreting organisms.

The argument of the work is suspended abruptly at this point, owing to Lyell's decision to publish this much before completing the remainder. As a result, the second volume is left incongruously with a frontispiece and a map having no relevance to the contents of the volume as published (p. 304). They were intended to epitomize the argument of what appeared a year later as the third volume.

VOLUME THREE
Principles of Reconstruction


The third volume (1833) opens with a long autobiographical preface, explaining the history of the work and the reasons for the delay in its completion, and -- between the lines -- defending the originality of his conclusions. An introductory section (chap. I) then reiterates the main features of his methodology, in answer to the criticisms that had been made since the publication of the first volume. As he wrote privately at the time, "I am grappling not with the ordinary arm of flesh, but with principalities and powers, with Sedgwick, Whewell and others, for my rules of philosophising, as contra-distinguished from them, and I must put on all my armour" CLYelll881, vol. 1, p. 376). The Pauline imagery, with its overtones of cosmic conflict, reflects Lyell's view of his work as an almost ideological crusade. He claims that the catastrophist belief in a discordance between present and past processes seriously inhibits discovery: "Never was there a dogma more calculated to foster indolence, and to blunt the keen edge of curiosity." With a fine rhetorical twist, he contrasts this with his own "earnest and patient endeavour to reconcile the former indications of change with the evidence of gradual mutations now in progress" (pp. 2-3). These, Lyell asserts, are "two distinct methods of theorizing," and he again uses a historical retrospect to defend his own method by pointing to the results it has achieved. In conclusion Lyell emphasizes that the "preliminary treatises contained in the first two volumes have been an essential groundwork for this third volume, which is the culmination of the whole work. A study of present processes is "the alphabet and grammar of geology"; only by first learning this language thoroughly is it possible to proceed to the real business of geology, that is, the decipherment of the past history of the earth (p. 7).

The first major section (chaps. II-IV) is therefore devoted to what might be termed -- by an extension of Lyell's metaphor -- the syntax of geology; namely, the ways of reconstructing the sequence of geological events. After an elementary summary of the main categories of rocks, Lyell concentrates attention on the Tertiary strata. [14] He emphasizes that the Tertiary strata in different areas are not all the same age, but represent many different parts of the "Tertiary epoch," and he hints that when the strata in areas of active volcanism and seismicity are taken into account "the line of demarcation between the actual [i.e., present] period and that immediately antecedent, is quite evanescent" (p. 22). This foreshadows his deliberate use of the Tertiary epoch as the chief testing ground for his steady-state system.

The validity of this test, however, depends on establishing that the Tertiary epoch is in fact representative of past geological time. In particular, Lyell has to explain away the apparent contrast between the widespread and rather uniform Secondary strata and the more localized distribution of the Tertiary strata. He interprets this as due to the contrast between a predominantly marine geography (in the part of the globe that now forms Europe) in the Secondary epoch and a predominantly continental geography, with more localized areas of marine deposition, in the same area during the Tertiary epoch.

He deals next with the apparently abrupt junctions that are often observed between successive groups of strata. These are not, he argues, the signs of occasional sudden changes in either the inorganic or the organic world; they are the natural result of perpetually shifting areas of deposition (hence the significance of the folding map, left incongruously in vol. 2, which shows how large a proportion of Europe was within such areas at one time or another during the Tertiary epoch). Recalling his earlier conclusion that the processes of species production and extinction are continually in operation everywhere, he illustrates the effect of "the working of this machinery" on the nature of the fossil record (p. 31). The sequence of strata in any given region is bound to show apparently sudden breaks, simply because the area of deposition has from time to time shifted elsewhere and then returned later, by which time the overall specific composition of the fauna and flora will have changed considerably. As so often, Lyell uses a familiar analogy from contemporary human affairs -- in this case the periodic censuses that had been instituted in Britain at the beginning of the century -- to clarify his geological concepts (Rudwick 1977). In other words, he concludes, the apparently sudden and simultaneous production of many new species or extinction of many others is an illusion due to the fragmentary record of the strata: "the whole economy of the existing causes" indicates clearly that the preservation of any more complete record "is not the plan of Nature" (p. 34). The geological record is inherently and necessarily fragmentary.

This leads to an analysis of the criteria by which the relative ages of strata, and hence of events in earth history, can be established. Lyell first mentions the fundamental but not always applicable criterion of the superposition of strata. He then denies that lithological character can be used, except with the greatest caution, because in principle the circumstances determining the nature of the sediment can never be universal, and in practice it is a matter of observation that distinctive rock types are frequently repeated in a sequence of strata. The character of the fossils is a more reliable criterion of contemporaneity, though it too must be used with caution. Recalling his earlier analysis of faunal and floral provinces and of the chances of preservation, he concludes that marine fossils are the most reliable, not only on account of their higher chance of fossilization, but also because their provinces are generally wider than those of terrestrial species.

These general principles are then applied in a preliminary fashion to the special problems of the Tertiary strata (chap. V). For this most recent epoch of earth history, Lyell selects the marine mollusks as the most appropriate indicators of geological age. This is partly because (as already mentioned) their shells are easily entombed and well preserved, and partly because their faunal provinces are extensive. But they are also selected because their species seem to have had much longer durations on average than those of, for example, the Mammalia.

This last reason is of great importance in Lyell's argument, for it hints at the radically original nature of his idea of geochronology. He is not concerned merely to identify strata by a few specially characteristic fossils, as most of his contemporaries were doing. He is attempting instead to set up a roughly quantitative geological chronometer, which will indicate not merely the relative order of strata but also their absolute ages, although only approximately and not in years (Rudwick 1978). The working of this chronometer depends crucially on his belief (set out in the second volume) that over the vast periods of geological time there is an essentially uniform rate of change in the organic world. Species originate and become extinct at various times and in various places, and they survive for longer or shorter periods; but given the ceaseless fluctuations of physical geography, on which the origin, continuation, and extinction of every species ultimately depend, the overall specific composition of the fauna and flora will show a statistical tendency to change continuously and uniformly. Hence it should be possible to estimate quantitatively the relative ages of any two deposits by comparing the proportion of extant to extinct species in each. The greater the proportion of extinct species, the greater the age of the fauna represented. Since a few extant species of marine mollusks can be found even in the earliest Tertiary strata, Lyell argues that the average duration of molluscan species is so great that they can be used to construct a chronometer for the whole of the Tertiary epoch.

Lyell does not discuss his method of reconstruction explicitly in terms of a geological chronometer, probably because that metaphor had figured so prominently in the earlier work of catastrophists such as the Swiss natural philosopher Jean-Andre Deluc, with whom Lyell would not have wished to associate himself. In this preliminary section he merely stresses the importance of accurate determinations of the species units of fossil faunas, and explains the value of the expert specific identifications that had been made for him by the Parisian conchologist Gerard Paul Deshayes. [15] The idea of using these faunal lists for a quantitative measure of the ages of Tertiary strata emerges more clearly in his summary of the divisions he adopts for that epoch: Pliocene, Miocene, and Eocene. These Greek-based names, which had been suggested to him by Whewell, are designed to embody the statistical principle: they refer respectively to the "major," "minor," and "dawn" components of "recent" species in the respective faunas. In fact, Lyell splits the Pliocene in two, and so defines four "periods," based on the percentage of extant species in a total fauna. In order backward from the Recent period (the period of man's existence), they are the Newer Pliocene (90-95%), Older Pliocene (c. 35-50%), Miocene (c. 18%), and Eocene (c. 3%). Lyell emphasizes that these periods are merely arbitrary divisions, adopted for convenience of description: their separation does not imply sudden changes in faunal character between them. Indeed, the discontinuities between the percentages defining the periods are indications of the huge gaps in time unrepresented by any known strata, and Lyell stresses that formations of intermediate character and age, which will blur the distinctness of his four periods, are therefore likely to be discovered in the future.

Superficially, this roughly quantitative treatment of fossils as indicators of geological age seems little different from the more conventional qualitative use of "characteristic fossils." (The three plates of fossils characteristic of the Pliocene, Miocene, and Eocene are purely illustrative, and were in any case designed by Deshayes, not by Lyell himself.) But as already suggested, there is a profound difference between them. This becomes clear in one brief passage in this section (p. 58). Lyell here maintains that the recognition of certain strata as, say, Eocene in date does not depend on the recognition of any characteristic Eocene fossils at all. The particular species present may be totally different from those of any previously known Eocene deposit, because the newly described strata may have been formed in a quite different faunal province in another part of the world. But the assemblage can still be recognized as Eocene in date if it contains a very low percentage of extant species. For the same "machinery" of a uniform rate of organic change will have affected both regions equally, although working on different species; the same chronometer can therefore be applied universally.

Lyell's use of a faunal chronometer for the reconstruction of earth history can now be seen as a crucial reason -- though certainly not the only reason -- for his insistence on the stability of species. Unless these faunal units remain morphologically stable and therefore taxonomically recognizable throughout the period of their existence, Lyell's quantitative assessment of the lapse of geological time would be invalid. To accept any process of gradual and continuous transmutation would be to undermine the method on which his demonstration of steady-state earth history depends.

Having analyzed the principles on which the geological past is to be interpreted "by reference to causes now in operation," Lyell is at last in a position to apply these principles to the positive evidence of the past. As already mentioned, he concentrates attention on the Tertiary epoch, primarily because it is nearest to the present. If he can demonstrate the adequacy of present processes for the explanation of this portion of geological time, and show that a steady-state system is applicable here, his readers will be more inclined to believe that the same principles may be valid for even earlier epochs.
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Re: Principles of Geology, by Charles Lyell

Postby admin » Fri Jul 17, 2015 12:09 am

PART 3 OF 3

Tertiary Earth-History

The main part of the third volume is therefore devoted to a detailed analysis of the Tertiary epoch. Lyell takes each of his four periods in turn, but he treats them in order backward from the most recent, explicitly for the methodological reason that "this retrospective order of inquiry is the only one which can conduct us gradually from the known to the unknown" (p. 62). Within each of his periods Lyell discusses the marine formations of that date, the freshwater deposits, and the contemporaneous igneous activity. This is not merely for the sake of orderly exposition: it is designed to demonstrate the uniform existence of the same processes and the same environments throughout the Tertiary epoch.

The first section, devoted to the Newer Pliocene, is also by far the longest (chaps. VI-XI). This reflects the greater attention that Lyell himself had given to these geologically young rocks. But he had become interested in them precisely because of their special theoretical significance. They are given great prominence in the Principles because they play a crucial role in breaking down the conceptual gap between past and present, smoothing the transition, and showing that no sudden change of geological or organic processes -- specifically, a "diluvial" episode -- has occurred in the recent past.

Lyell first describes the Newer Pliocene marine strata he had studied in Sicily (chap. VI). He stresses three points about them: the insignificant proportion of extinct molluscan species which they contain, the evidence that they accumulated very slowly and therefore represent an extremely long period of time, and their remarkable degree of elevation above sea level in central Sicily. He then suggests that similar, geologically quite recent strata underlie the huge volcanic cone of Etna (chap. VII). He goes on to analyze in detail the structure of Etna itself. Lyell argues that it does not support von Buch's elevation-crater theory of a sudden paroxysmal elevation, but that it has been built up extremely gradually by the successive extrusion of lava flows, just like those that have been observed during historic times (chap. VIII). He then attempts to estimate, very roughly, the age of the volcano, and he concludes that it "must have required an immense series of ages anterior to our historic periods, for its growth; yet the whole must be regarded as the product of a modern portion of the newer Pliocene epoch" (p. 101).

This lengthy analysis of Etna is thus an important part of Lyell's whole argument. His geological chronometer based on fossil mollusks gives him a means of dating the Tertiary epoch semi- quantitatively, but it is Etna which enables him to hint at a calibration of this chronometer in terms of the years of human history (Rudwick 1969). He prudently avoids hazarding in print any figures for this calibration, for it could be only slightly better than a guess. [16] But in any case he makes clear that the time scale of Tertiary history is almost unimaginably vast in comparison with that of human history. Such a vivid illustration of the magnitude of geological time is a valuable aid in his task of persuading his readers to accept the scientific implications of such a time scale. This in part explains his choice of a picture of Etna for the frontispiece of the second volume, which was originally intended to be the final volume of the work (the picture was published incongruously in the truncated second volume).

This does not exhaust the significance of Etna, however. On the Huttonian theory explained in the first volume, the eruptive action of a volcano is only the surface manifestation of the deep-seated processes which are also responsible for the elevation of land. Therefore, Lyell argues, the elevation of the Newer Pliocene strata in central Sicily could have taken place very gradually over a long period of time by a series of intermittent earthquakes, just as the growth of Etna was proceeding during the same period by a series of intermittent eruptions (chap. IX). This argument is important, because (as already mentioned) it will enable him to maintain that any greater degree of elevation, even of the highest mountain ranges, is in principle explicable in similar terms. The gradual elevation of the Sicilian strata is also supported by the form of the valleys and ancient sea cliffs cut into them, and indirectly by the nature of the fauna and flora now inhabiting the region.

The supposed contrast between present and past is also attacked at other points on the basis of these Sicilian strata. Lyell infers that their elevation is due to the subterranean injection of vast masses of molten material, which on cooling form the crystalline igneous rocks that are commonly seen in the eroded cores of older mountain ranges. Thus he can argue (like Hutton) that the formation of granite and similar rocks is not solely a feature of more primitive periods of earth history, but is a process still in operation.

Turning from Sicily to the volcanic areas of Italy (chap. X), Lyell continues the same argument. He criticizes those who contrast the insignificant scale of modern changes with the vast scale of ancient geological effects, pointing out that they fail to take account of the magnitude of the time scale during which the latter effects have been produced. A brief survey of Newer Pliocene marine strata in other parts of the world leads Lyell to comment that these strata are generally visible above sea level only in areas subject to earthquakes, as indicated by his theory of elevation.

Lyell then discusses the nonmarine deposits of Newer Pliocene age (chap. XI). He criticizes particularly the idea of a single "alluvial epoch" (which had been closely associated with the notion of a "diluvial" episode), pointing out that "alluvial" deposits such as coarse gravels have been formed at many periods. The huge "erratic blocks" of the Alps and elsewhere -- rocks often left perched on hilltops tens or hundreds of miles from their sources -- were more difficult for him to explain. [17] Lyell rejects any suggestion that they might have been transported by a vast tidal wave actuated by the sudden elevation of a mountain range in another part of the globe. He can ascribe those scattered over northern Europe to the actualistic agency of floating marine icebergs; indeed this can be integrated neatly with his climatic theory and his concept of ever-shifting areas of marine deposition. But for the erratics spread over the low ground around the Alps, and even up on to the slopes of the Jura hills beyond the Swiss plain, he has to resort to a rather awkward conjecture: he suggests that they were transported by freshwater icebergs that were suddenly (and catastrophically!) released by the collapse of barriers damming temporary Alpine lakes.

The Older Pliocene period is analyzed more briefly (chaps. XII-XIV). Lyell's description of the celebrated Sub-Apennine strata in Italy, and of the English strata to which he attributes the same age, needs no special comment. To illustrate the volcanic activity of the period, he places here the extinct but well-preserved cones of Catalonia and the Eifel, which he had visited in 1830 and 1831. He uses a picture of some of the Catalonian cones as the frontispiece of the third volume, but the reason for this choice emerges more clearly in his later discussion of the similar cones in central France.

The Miocene period is also treated briefly (chaps. XV, XVI). Lyell describes various marine, freshwater, and volcanic rocks which he attributes to this period. Recalling the arbitrary character of his periods and the implicit temporal gaps between them, he suggests that certain deposits (at Montpellier, in the south of France) may be of an age intermediate between the Miocene and the Older Pliocene: "We are fully prepared for the discovery of such intermediate links" (p. 216).

Lyell's analysis of the Eocene period (chaps. XVII-XX) reverses the usual order of topics by describing the freshwater deposits of central France (chap. XVl1) before discussing the better-known formations -- many of them marine -- in the Paris basin (chap. XVIII). This enables him to introduce an interpretation of the latter which avoids any need for postulating catastrophic events. For these Parisian deposits, with their abrupt alternations of freshwater and marine strata, had been central to Cuvier's theory of sudden continent-wide changes to physical geography and consequently to terrestrial faunas: at this point Lyell was up against one of the strongholds of catastrophism. He therefore argues that the exclusively freshwater deposits to central France show that no marine incursions ever penetrated to that area during Eocene time. He is then able to use Prevost's recent critique of Cuvier's interpretation to show how the freshwater and marine strata around Paris could have accumulated simultaneously in different parts of the area, as in a modern gulf or estuary, without sudden changes of sea level. This reinterpretation, as he points out, makes it "more easy to explain the manner of their origin and to reconcile their relations to the agency of known causes" (p. 248). Moreover, in view of the very high proportion (97%) of extinct species among the marine mollusks to these strata, Lyell argues that it is hardly surprising that all the vertebrate fossils, without exception, are also extinct. Notwithstanding Cuvier's opinion, no general revolutions need be invoked to account for this: it merely reflects a much higher rate of change in vertebrate faunas than in molluscan faunas. Summarizing this section, Lyell stresses the normality of the world revealed by his interpretation of the Eocene deposits. They bear witness to a period as tranquil as the present; contrary to what the directionalists tended to suggest, "we are naturally led to conclude, that the earth was at that time in a perfectly settled state, and already fitted for the habitation of man" (p. 255).

Under the heading of Eocene volcanic rocks, Lyell next discusses the celebrated volcanic areas of central France (chap. XIX), drawing freely on the great memoir (1827) by the English geologist (and political economist) George Scrope, which Lyell had earlier reviewed and then followed in the field (Rudwick 1974). He stresses particularly the classic evidence that the volcanic eruptions had been of many different dates; but he assigns a very early age, namely Miocene, even to the most recent eruptions. He argues that the extremely fresh appearance of some of the volcanic cones -- as perfectly preserved as the minor cones he had seen on the slopes of Etna, dating from the past few centuries -- is no indication of their real age. His reason for this very surprising conclusion soon emerges: he is concerned to attack the belief that these volcanic rocks can be sharply divided into antediluvial and postdiluvial categories. This is the more necessary because of Sedgwick's recent support for the neodiluvial catastrophism of the leading Parisian geologist Leonce Elie de Beaumont. By arguing, however implausibly, for the great geological age of even the youngest volcanic cones in central France, Lyell is able to deny once more that there is any evidence for a geologically recent "diluvial" episode; for any such event would certainly have eroded or swept away such cones of loose unconsolidated material. This explains the significance of the similar cones in Catalonia, an illustration of which Lyell chose (as already mentioned) for the frontispiece of the third volume. To combat the possible revival of Mosaic geology on a more scientific basis, Lyell cites Fleming in support of the view that the scriptural Flood was in any case recorded in terms entirely different in character from the violent diluvial episode postulated by his scientific opponents.

A straightforward description of the Eocene strata in England (chap. XX) leads to a long digression on the mode of elevation and erosion of the Weald area in southern England, which separates the main areas of Eocene strata (chaps. XXI, XXII). The purpose of this digression is again to combat recent catastrophist interpretations of the area, notably by Buckland. Lyell argues that there was no sudden episode of elevation of the strata or of diluvial erosion of the valleys. The anticlinal elevation of the Weald was very gradual; the Chalk and earlier rocks were eroded from the center chiefly by gradual marine erosion; and the material so produced contributed to the equally gradual and simultaneous accumulation of the Tertiary strata in adjacent areas (the London and Hampshire basins).

Pre-Tertiary Earth-History

This concludes Lyell's actualistic and steady-state interpretation of Tertiary earth history. His analysis of Secondary strata (chap. XXIII) is very brief. This is certainly not because in 1833 they were less well known than the Tertiary: on the contrary, they were much better known. Nor is it primarily because an equally lengthy treatment of Secondary periods would have required yet another volume. The main reason for his brevity is strategic. Having demonstrated the adequacy of present processes at their present level of intensity for the interpretation for Tertiary time, it is sufficient for the purpose of his overall strategy to treat the Secondary periods summarily, merely "to show that the rules of interpretation adopted by us for the tertiary formations, are equally applicable to the phenomena of the secondary series" (p. 324).

On Deshayes's authority he accepts the magnitude of the faunal discontinuity between the Eocene strata and even the uppermost strata of the underlying Chalk series (those at Maastricht in the Netherlands), there being no molluscan species in common. He attributes this, however, not to any sudden episode of mass extinction and subsequent faunal replacement, but to a huge gap in the fossil record. He suggests that it might represent a period of time even greater than that which separates the earliest Eocene deposits from the present day. This inference, however startling to modern eyes, shows the consistency with which Lyell is prepared to apply the principle of a uniform rate of change in the organic world, and the geological chronometer founded upon it. On that chronometer the period from Eocene to the present has been long enough to produce a 97% turnover in the molluscan fauna; therefore, since the Chalk/Eocene discontinuity is marked by a 100% turnover in species, it must represent an even longer period.

For the Secondary strata in general Lyell stresses again the reasons for their apparent contrast to the Tertiary. The geography of the Secondary epoch in the area that now forms Europe was predominantly marine. Since large areas of that ancient sea floor have by now been lifted above sea level, it is only natural, he argues, that some Secondary formations (for example, the Chalk) should maintain a uniform character over very wide areas, in striking contrast to the patchy distribution of the Tertiary deposits. Similarly, the longer time that has elapsed since their deposition is also sufficient to account for their generally greater degree of consolidation and tectonic disturbance. None of these features, Lyell implies, can be taken to represent conditions or processes different from those of Tertiary time. The stability of the "system" was thus maintained in Secondary earth history as much as in the subsequent Tertiary.

Before proceeding to the Primary rocks, and the conclusion of the Whole work, Lyell digresses to argue against Elie de Beaumont's recent theory of the paroxysmal elevations of mountain ranges (chap. XXIV). Here again Lyell asserts that the key to a correct interpretation of the phenomena is a proper appreciation of the magnitude of geological time and the fragmentary nature of the succession of strata. For the suddenness attributed to any given episode of elevation depends on proving the brevity of the time interval separating the youngest strata affected by the movement from the oldest strata unaffected. On Lyell's view of the fragmentary nature of the record, such intervals cannot be shown to have been short at all: "Even if all the facts appealed to by [Elie] de Beaumont are correct, his intervals are of indefinite extent" (p. 344).

Having disposed of this most recent -- and most strictly scientific -- challenge to his concept of uniformity, Lyell turns finally to the Primary rocks (chaps. XXV; XXVl), which most of his contemporaries took to be the oldest in the earth's crust. He immediately criticizes the term, claiming that it includes rocks of many different ages, not all of them older than the Secondary strata. "Unstratified Primary" rocks, such as granite, deserve the Huttonian name Plutonic to denote their deep-seated igneous origin. Like Hutton, Lyell maintains that granite is not "the oldest of rocks," predating the appearance of life on earth. On the contrary, "it is now ascertained that this rock has been produced again and again, at successive eras" (p. 357). It is often seen penetrating Secondary strata, and it may be assumed to be forming even at the present time beneath the main centers of volcanism and elevation. Lyell claims that the so-called Trap rocks, which were generally agreed to be intrusive rocks associated with ancient volcanic activity, are likewise not confined to earlier periods, for they are found among even the Newer Pliocene strata.

The "stratified Primary" rocks such as schist and gneiss are somewhat more difficult for Lyell to explain. In some respects they look like ordinary sediments, yet they often seem to merge into granite. This apparent contradiction can be resolved, Lyell argues, only by adopting "the Huttonian hypothesis" of what he terms metamorphism. Schist and gneiss are sediments that have been altered by heat in the proximity of molten granite, in a process analogous to small-scale laboratory experiments and to the larger natural experiments of contact metamorphism near igneous dikes.

Lyell therefore proposes that the stratified Primary rocks should be renamed Metamorphic. For the unstratified Primary the name Plutonic is already available. For the two categories together, that is for all Primary rocks, Lyell proposes the term Hypogene, or "nether-formed." These terminological proposals are far from trivial. They are introduced to stress Lyell's contention that all the rock types commonly regarded as characteristic of, or even confined to, the earliest periods of earth history can in fact be formed in any period, including the present. The so-called Primary is therefore not primary at all.

This conclusion is illustrated in the table and diagram that immediately follow this final chapter (pp. 386-88). Under each period of geological time Lyell lists examples not only of "alluvial," marine, and freshwater deposits, and volcanic rocks, but also of visible or inferred Hypogene rocks, both Plutonic and Metamorphic. The table, and the diagram that complements it visually, epitomize neatly the steady-state system that emerges from the whole work. All categories of rock, and therefore all causal processes, have existed uniformly in all periods of earth history. Those periods are only carried back as far as the Carboniferous, but in 1833 that was still the earliest period with a clearly defined stratal succession. Significantly, however, Lyell extends the "Carboniferous Group" downward to include even the poorly known "Grauwacke and Transition limestone," the oldest strata he recognized (p. 393) [18] With the assimilation of the Transition strata into the Secondary period, and the reinterpretation of all the so-called Primary strata as either igneous or metamorphic, the chronicle of earth history is thus left -- as Hutton had famously expressed it -- without vestige of a beginning.

In his "concluding remarks," Lyell acknowledges the Huttonian affinities of his system, but defends himself against the charge of advocating an eternalistic -- and therefore potentially atheistic -- view of the natural world. He protests that this is as unfair to him as it was to Hutton before him. Using the conventional analogy between space in astronomy and time in geology, he stresses that his apparent eternalism merely expresses the intrinsic limits of human knowledge. We must be prepared to find that, as in exploring space, so "in time also, the confines of the universe lie beyond the reach of mortal ken" (p. 393). Echoing Hutton once more, he claims that the stable system of the earth that his interpretation of geology has disclosed shows its designfulness precisely by virtue of its stability. To assume that we shall ever find evidence of its beginning or its end would be "inconsistent with a just estimate of the relations which subsist between the finite powers of man and the attributes of an Infinite and Eternal Being" (p. 385). Far from being a merely formal or conventional expression of minimal religious sentiment, this is but the culminating example of the deistic and providentialist language with which the Principles is suffused throughout. Lyell was certainly no orthodox Christian; but nor was he the atheistic or antireligious figure that he has sometimes been made out to be in subsequent myth making.

It is appropriate that Lyell's vast extended argument should conclude with an unmistakably Huttonian echo. It was clearly Hutton's vision that inspired him to construct an even grander system on the firmer foundations of the geology of his own time -- a system of almost infinite complexity, but one in which both inorganic and organic processes balance and interact to produce a perpetual dynamic stability.

THE LEGACY OF THE PRINCIPLES

In the foregoing analysis of the Principles -- and even more in the text and footnotes of the volumes themselves -- the references to the work of other geologists should make it clear that Lyell's book was not launched into a vacuum of geological theory and practice. It was intended by Lyell, and perceived by others, as a contribution to an already lively debate. By pressing some interpretative principles of the science to their limit, however, and by proposing a radically unorthodox view of the whole shape of earth history, the Principles certainly sharpened that debate and made its terms more explicit.

The process of public dialogue between Lyell and other geologists began with the early reviews of the first volume (1830), and Lyell's response began to become explicit when the third volume was published (1833). By that time the first two volumes were already in a second edition. The next edition of the whole work, which appeared in 1834, was therefore termed the third; the fourth was published in 1835 and the fifth in 1837. The rapid succession bear witness both to the success of the work and to Lyell's rapid uptake of the latest research, by himself and others, in the service of his overall vision of geology. However, the steady-state system that had held the work together found few if any wholehearted adherents. This is reflected in Lyell's decision, in the later 1830s, to separate the work into two distinct parts. Reverting to the popular format that he had initially planned for the Principles, he recast the contents of the original third volume as the Elements of Geology (1838), which summarized the reconstruction of earth history in an introductory fashion. The next (sixth) edition of the Principles (1840) was correspondingly truncated, and confined to setting out Lyell's analysis of "causes now in operation." Both works continued their separate publishing careers, with much updating, to the end of Lyell's life (he died in 1875).

The debate between Lyell and his critics, which was particularly lively in the early years, was never sharply polarized into factions or parties: there was no clear-cut controversy between "catastrophists" and "uniformitarians," if only because those terms meant so many different things to different people. Geologists responded to Lyell's work in many different ways: adopting some points, rejecting others; being persuaded by some of Lyell's arguments and remaining unconvinced by others. In particular, as already mentioned, Lyell's steady-state system never found any significant sup porters (Bartholomew 1976, 1979). In this respect it was unquestionably Lyell's directionalist opponents who were the more successful in swaying geological opinion. It was their developmental vision of earth history that, later in the century, assimilated an evolutionary conception of the history of life -- as Lyell had perceptively anticipated, and feared. [19]

On the other hand, Lyell's persuasive reinterpretation of geological evidence, in terms of "causes now in operation" operating over humanly unimaginable spans of time, did gradually affect, and indeed transform, the practice of geology during the decade or two that followed the first edition. [20] The sheer scope of Lyell's vision, and the immense range of the "worked examples" that he offered, were in the end profoundly influential. The heuristic value of seeking whenever possible for actualistic and noncatastrophist explanations has been a fundamental and taken-for-granted principle of the earth sciences ever since. In recent years, however, some geologists have come to recognize once more what Lyell's original critics saw very clearly: namely, that it may at times be both necessary and legitimate to invoke causal processes more intense than those we can observe, or even those of kinds that we have never observed, if the evidence warrants it. But even for neo-catastrophists, as for their nineteenth-century forerunners, the Lyellian approach remains a salutary brake on undisciplined speculation. Charles Lyell, and his Principles, remain forces to be reckoned with.

-- Martin J. S. Rudwick

_______________

Notes:

1. This introduction is adapted, by permission of the History of Science Society, from my article "The Strategy of Lyell's Principles of Geology" (1970); but it has been substantially revised to take account of subsequent research, particularly of the papers given at the Charles Lyell Centenary Symposiun in London in 1975 (published in British Journal of the History of Science, vol. 9, no 2, 1976). This revision was supported by the National Science Foundation under grant no. SE8-88-96206.

2. The first volume (1972) of Wilson's biography is a valuable source of factual information. His broader interpretation of Lyell's significance for the history of science is more fully expressed in a later article (1980). The differences between Wilson's interpretation of the Principles and that put forward in this Introduction are too far-reaching to be discussed here.

3. Anyway his proposed title Conversations on Geology was preempted by an anonymous work (1828) of just the kind he wanted to combat, which gave what would now be termed "equal time" to the scientifically worthless "Scriptural" geologists of the day.

4. Lyell added a glossary of scientific terms to the third volume (Appendices, 61-83) at the request of some of his nongeological readers. It can well serve the same function for modern readers, including those who are geologists, because many of Lyell's technical terms are now obsolete or have changed their meaning.

5. Lyell's extensive field trips on the Continent in 1830, 1831, and 1832 -- the last being combined with his honeymoon!-were also in time to benefit the first edition of the Principles, but did not have such a profound impact on him.

6. The singular in the printed text is either a misreading of the manuscript or an inadvertent slip of Lyell's pen: the plural used in the rest of the sentence makes the sense clear.

7. So called because they claimed the literal scientific accuracy of Genesis, one of the Old Testament books traditionally attributed to Moses himself.

8. "Secondary" was roughly equivalent to the Mesozoic and Upper Paleozoic formations of modern geologists. In terms of the formations in Europe that formed the reference series for all geologists in the 1830s, it extended from the Chalk (in modern terms, Cretaceous) at the top down through the Old Red Sandstone (in modern terms, Devonian) at the bottom.

9. Lyell's contemporaries fully realized the implications of the vast cyclicity he was postulating. This is particularly clear from the famous (and in modern times frequently reproduced) lithograph that Henry De la Beche drew and distributed widely among English geologists, in order to ridicule Lyell's ideas on this point. It showed a "Professor Ichthyosaurus" lecturing- in the post-human-future -- on the subject of a (fossilized) human skull (Rudwick 1975).

10. Lyell referred privately to von Hoff's "German plodding perseverance" and claimed that "he helped me not to my scientific view of causes" (Lyell 1881, vol. 1, 268--69). Though bluntly expressed, the comment was justified, because von Hoff had arranged his data in a purely descriptive manner, rather than in terms of their causal origins (Rudwick 1977).

11. The Temple of Serapis continued to act as frontispiece of the Principles throughout Lyell's life; in later editions it was also embossed in gold, like a secular icon, on the front cover of the book.

12. Lyell changed his mind on this point while visiting the area in 1834 (Lyell 1881, vol. 1,436), and made it the subject of his substantial first paper (1835) to the Royal Society in London.

13. This is the point at which Darwin later out-Lyelled Lyell, with his interpretation of coral reefs and atolls as the signs of successive stages in the submersion of a continent (Stoddart 1976)

14. "Tertiary" survives in the vocabulary of modern geologists as an informal synonym for Cenozoic. In the 18308 it was taken to comprise the relatively recent formations above and therefore younger than the Secondary (except the "Recent" deposits assumed to be coeval with man).

15. Deshayes's tables form the empirical basis of Lyell's analysis, and are printed as a long appendix at the end of the volume (Appendices, 1-45), along with faunal lists of Lyell's own collections of Tertiary assemblages, which Deshayes had identified for him (Appendices, 53-60).

16. In private correspondence, and later in his lectures at King's College, London, he estimated the age of the volcano at about sixty thousand to seventy thousand years, and the underlying "Newer Pliocene" strata at about a hundred thousand years (Rudwick 1975a; Tasch 1977). Though modest by modern standards, such figures were humanly vast enough to be highly impressive in the 18308. Implicitly they extended the total length of recorded earth history into many millions of years, if not into tens or hundreds of millions. As mentioned above, Lyell's contemporaries were not averse to such figures, but he was right to think that they had not yet assimilated all the implications of such a vast time scale.

17. Erratics remained one of the most formidable problems for a Lyellian interpretation until the formulation of the glacial theory in the 1840s and later. This theory postulated a geologically recent "Ice Age," during which erratics could have been transported on glaciers and ice sheets vastly extended beyond their present remnants (Rudwick 1970).

18. The Transition or Grauwacke strata, below and therefore older than the Carboniferous as usually defined, included the oldest formations in which any fossils had been found. In 1835, only two years after this volume of the Principles was published, Murchison proposed the term "Silurian" for the younger and relatively fossiliferous Transition strata (Secord 1986; Rudwick 1985). The widespread recognition of the distinctive Silurian fauna first began to erode the plausibility of Lyell's steady-state interpretation of the fossil record.

19. Lyell himself eventually accepted this, but only belatedly and reluctantly, in the tenth edition of the Principles (1867), published after Darwin's Origin of Species (1859).

20. The nature and timing of Lyell's influence outside the English-speaking world is an important topic on which little historical research has yet been done. The Principles and even the Elements were not translated very promptly into either French or German -- the major scientific languages of the early and late nineteenth century respectively -- but of course the impact of his work could have spread in other ways.

BIBLIOGRAPHY

Apart from the Victorian edition of Lyell's correspondence, which has been quoted frequently in the above introduction, the following list is confined to modern (secondary) historical works. These in turn contain full references to the nineteenth-century (primary) sources that have been cited. Lyell's own explicit sources are cited in the footnotes to his three volumes.

Bartholomew, Michael, 1973. Lyell and evolution: an account of Lyell's response to the prospect of an evolutionary ancestry for Man. British Journal for the History Of Science, vol. 6, 261-303.

____, 1976. The non-progression of non-progression: two responses to Lyell's doctrine. Ibid., vol. 9, 166-74.

____, 1979. The singularity of Lyell. History of Science, vol. 17, 276-93.

Brush, Stephen G., 1987. The nebular hypothesis and the evolutionary worldview. Ibid., vol. 25, 245- 78.

Cannon, W. Faye, 1976. Charles Lyell, radical actualism, and theory. British Journal for the History Of Science, vol. 9, 104-20.

Corsi, Pietro, 1978. The importance of French transformist ideas for the second volume of Lyell's Principles of Geology. Ibid., vol. 11, 221-44.

Gould, Steven Jay, 1987. Time's Arrow, Time's Cycle (Cambridge, Mass.: Harvard University Press).

Laudan, Rachel, 1982. The role of methodology in Lyell's science. Studies in the History and Philosophy of Science, vol. 13, 215-49.

____, 1987. From Mineralogy to Geology, The Foundations of a Science, 1650-1830 (Chicago and London: University of Chicago Press).

Lawrence, Philip, 1977. Heaven and earth: the relation of the nebular hypothesis to geology. In Wolfgang Yourgrau and Allen D. Breck (eds.), Cosmology, History and Theology (New York: Plenum), 253-81.

Lyell, Mrs. [Katherine) (ed.), 1881. Life Letters and Journals Of Sir Charles Lyell, Bart. (London: John Murray), 2 vols.

McCartney, Paul J., 1976. Charles Lyell and G. B. Brocchi: a study in comparative historiography. British Journal for the History of Science, vol. 9, 175-89.

Morrell, J. B., 1976. London institutions and Lyell's career: 1820-41. Ibid., 132-46.

Ospovat, Alexander M., 1976. The distortion of Werner in Lyell's Principles of Geology. Ibid., 190-98.

Ospovat, Dov, 1977. Lyell's theory of climate. Journal of the History of Biology, vol. 10, 317-39.

Porter, Roy, 1976. Charles Lyell and the principles of the history of geology. British Journal for the History Of Science, vol. 9, 91-103.

____, 1977. The Making of Geology: Earth Science in Britain, 1660-1815 (Cambridge: Cambridge University Press).

____, 1982. Charles Lyell: the public and private faces of science. Janus, vol. 69, 29-50.

Rudwick, Martin J. S., 1969. Lyell on Etna, and the antiquity of the earth. In Cecil J. Schneer (ed.), 1bward a History of Geology (Cambridge, Mass.: M.I.T. Press), 288-304.

____, 1970a. The strategy of Lyell's Principles Of Geology. Isis, vol. 61, 4-33.

____, 1970b. The glacial theory. History of Science, vol. 8, 136-57.

____, 1971. Uniformity and progression: reflections on the structure of geological theory in the age of Lyell. In Duane H. D. Roller (ed.), Perspectives in the History Of Science and Technology (Norman, Okla.: Oklahoma University Press), 209-27.

____,1974. George Poulett Scrope on the volcanoes of Auvergne: Lyellian time and political economy. British Journal for the History of Science, vol. 7, 205-42.

____, 1975a. Charles Lyell F.R.S. (1797-1875) and his London lectures on geology, 1832-33. Notes and Records Of the Royal Society of London, vol. 29, 231-63.

____, 1975b. Caricature as a source for the history of science: De la Beche's anti-Lyellian sketches of 1831. Isis, vol. 66, 534-60.

____, 1976. The emergence of a visual language for geological science, 1760-1840. History of Science, vol. 14, 149-95.

____, 1977. Historical analogies in the early geological work of Charles Lyell. Janus, vol. 84, 89-107.

____, 1978. Charles Lyell's dream of a statistical palaeontology. Palaeontology, vol. 21, 225-44.

____, 1985. The Great Devonian Controversy: The Shaping of Scientific Knowledge among Gentlemanly Specialists (Chicago and London: University of Chicago Press).

Ruse, Michael, 1976. Charles Lyell and the philosophers of science. British Journal for the History of Science, vol. 9, 121-31.

Secord, James A., 1986. Controversy in Victorian Geology, The Cambrian-Silurian Dispute (Princeton: Princeton University Press).

Stoddart, D. R., 1976. Darwin, Lyell, and the geological signifcance of coral reefs. British Journal for the History of Science, vol. 9, 199-218.

Tasch, Paul, 1977. Lyell's geochronological model: published year values for geological time. Isis, vol. 68, 440-41.

Wilson, Leonard G., 1972. Charles Lyell. The Years to 1841. The Revolution in Geology (New Haven: Yale University Press).

____, 1980. Geology on the eve of Charles Lyell's first visit to America, 1841. Proceedings of the American Philosophical Society, vol. 124, 168-202.
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Re: Principles of Geology, by Charles Lyell

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Present state of the Temple of Serapus al Puzzuoli

London, Published by John Murray, Albemarle St., June 1830

PRINCIPLES OF GEOLOGY, BEING AN ATTEMPT TO EXPLAIN THE FORMER CHANGES OF THE EARTH'S SURFACE, BY REFERENCE TO CAUSES NOW IN OPERATION.

BY CHARLES LYELL, ESQ., F.R.S. FOR. SEC. TO THE GEOL. SOC., &c.

IN TWO VOLUMES.

VOL. I.

LONDON:

JOHN MURRAY, ALBEMARLE-STREET,

MDCCCXXX.

LONDON,
Printed by WILLIAM CLOWES,
Stamford Street.

CONTENTS

• Front Matter
• Chapter 1: Geology defined – Compared to History – Its relation to other Physical Sciences – Its distinctness from all – Not to be confounded with Cosmogony
• Chapter 2: Oriental Cosmogony – Doctrine of the successive destruction and renovation of the world – Origin of this doctrine – Common to the Egpytians – Adopted by the Greeks – System of Pythagoras – Of Aristotle – Dogmas concerning the extinction and reproduction of genera and species – Strabo's theory of elevation by earthquakes – Pliny – Concluding remarks on the knowledge of the Ancients
• Chapter 3: Arabian writers of the Tenth century – Persecution of Omar – Cosmogony of the Koran – Early Italian writers – Fracastoro – Controversy as to the real nature of organized fossils – Fossil shells attributed to the Mosaic deluge – Palissy – Steno – Scilla – Quirini – Boyle – Plot – Hooke's Theory of Elevation by earthquakes – His speculations on lost species of animals – Ray – Physico-theological writers – Woodward's Diluvial Theory – Burnet – Whiston – Hutchinson – Leibnitz – Vallisneri – Lazzoro Moro – Generelli – Buffon – His theory condemned by the Sorbonne as unorthodox – Buffon's declaration – Targioni – Ardinino – Michell – Catcott – Raspe – Fortis – Testa – Whitehurst – Pallas – Saussure
• Chapter 4: Werner's application of Geology to the art of Mining – Excursive character of his lectures – Enthusiasm of his pupils – His authority – His theoretical errors – Desmarest's map and description of Auvergne – Controversy between the Vulcanists and Neptunists – Intemperance of the rival Sects – Hutton's theory of the Earth – His discovery of granite veins – Originality of his views – Why opposed – Playfair's illustrations – Influence of Voltaire's writings on Geology – Imputations cast on the Huttonians by Williams, Kirwau, and De Luc – Smith's map of England – Geological Society of London – Progress of the Science in France – Growing importance of the study of organic remains
• Chapter 5: Review of the causes which have retarded the progress of Geology – Effects of prepossessions in regard to the duration of past time – Of prejudices arising from our peculiar position as inhabitants of the land – Of those occasioned by our not seeing subterranean changes now in progress – All these causes combine to make the former course of Nature appear different from the present – Several objections to the assumption, that existing causes have produced the former changes of the earth's surface, removed by modern discoveries
• Chapter 6: Proofs that the climate of the Northern hemisphere was formerly hotter – Direct proofs from the Organic remains of the Sicilian and Italian strata – Proofs from analogy derived from extinct Quadrupeds – Imbedding of Animals in Icebergs – Siberian Mammoths – Evidence in regard to temperature, from the fossil remains of tertiary and secondary rocks – From the plants of the coal formation
• Chapter 7: On the causes of vicissitudes in climate – Remarks on the present diffusion of heat over the globe – On the dependence of the mean temperature on the relative position of land and sea – Isothermal lines – Currents from equatorial regions – Drifting of Icebergs – Different temperature of Northern and Southern hemispheres – Combination of causes which might produce the extreme cold of which the earth's surface is susceptible – On the conditions necessary for the production of the extreme of heat, and its probable effects on organic life
• Chapter 8: Geological proofs that the geographical features of the northern hemisphere, at the period of the deposition of the carboniferous strata, were such as would, according to the theory before explained, give rise to an extremely hot climate – Origin of the transition and mountain limestones, coal-sandstones, and coal – Change in the physical geography of northern latitudes, between the era of the formation of the carboniferous series and the lias – Character of organic remains, from the lias to the chalk inclusive – State of the surface when these deposits originated – Great accession of land, and elevation of mountain-chains, between the consolidation of the newer secondary and older tertiary rocks – Consequent refrigeration of climate – Abrupt transition from the organic remains of the secondary to those of the tertiary strata – Maestricht beds – Remarks on the theory of the diminution of central heat
• Chapter 9: Theory of the progressive development of organic life considered – Evidence in its support wholly inconclusive – Vertebrated animals in the oldest strata – Differences between the organic remains of successive formations – Remarks on the comparatively modern origin of the human race – The popular doctrine of successive development not confirmed by the admission that man is of modern origin – In what manner the change in the system caused by the introduction of man affects the assumption of the uniformity of the past and future course of physical events
• Chapter 10: Division of the subject into changes of the organic and inorganic world – Inorganic causes of change divided into the aqueous and igneous – Aqueous causes – Destroying and transporting power of running water – Sinuosities of rivers – Two streams when united do not occupy a bed of double surface – Heavy matter removed by torrents and floods – Recent inundations in Scotland – Effects of ice in removing stones – Erosion of chasms through hard rocks – Excavations in the lavas of Etna by Sicilian rivers – Gorge of the Simeto – Gradual recession of the cataracts of Niagara – Speculations as to the time required for their reaching Lake Erie
• Chapter 11: Action of running water, continued – Course of the Po – Desertion of its old channel – Artificial embankments of the Po, Adige, and other Italian rivers – Basin of the Mississippi – Its meanders – Islands – Shifting of its course – Raft of the Atchafalaya – Drift wood – New-formed lakes in Louisiana – Earthquakes in the valley of the Mississippi – Floods caused by landslips in the White mountains – Bursting of a lake in Switzerland – Devastations caused by the Anio at Tivoli
• Chapter 12: Difference between the transporting power of springs and rivers – Many springs carry matter from below upwards – Mineral ingredients most abundant in springs – Connexion of mineral waters with volcanic phenomena – Calcareous springs – Travertin of the Elsa – Baths of San Vignone, and of San Filippo, near Radicofani – Spheroidal structure in travertin, as in English magnesian limestone – Bulicami of Viterbo – Lake of the Solfatara, near Rome – Travertin at Cascade of Tivoli – Ferruginous springs – Cementing and colouring property of iron – Brine springs – Carbonated springs – Disintegration of Auvergne granite – Caverns in limestone – Petroleum springs – Pitch lake of Trinidad
• Chapter 13: Reproductive effects of running water – Division of deltas into lacustrine, mediterranean, and oceanic – Lake deltas – Growth of the delta of the Rhone in the Lake of Geneva – Chronological computations of the age of deltas – Recent deposits in Lake Superior – Deltas of inland seas – Rapid shallowing of the Baltic – Arguments for and against the hypothesis of Celsius – Elevated beaches on the coast of Sweden – Marine delta of the Rhone – Various proofs of its increase – Stony nature of its deposits – Delta of the Po, Adige, Isonzo, and other rivers entering the Adriatic – Rapid conversion of that gulf into land – Mineral characters of the new deposits – Delta of the Nile – Its increase since the time of Homer – Its growth why checked at present
• Chapter 14: Oceanic deltas – Delta of the Ganges and Burrampooter – Its size, rate of advance, and nature of its deposits – Formation and destruction of islands – Abundance of crocodiles – Inundations – Delta of the Mississippi – Deposits of drift wood – Gradual filling up of the Yellow Sea – Rennell's estimate of the mud carried down by the Ganges – Formation of valleys illustrated by the growth of deltas – Grouping of new strata in general – Convergence of deltas – Conglomerates – Various causes of stratification – Direction of laminae – Remarks on the interchange of land and sea
• Chapter 15: Destroying and transporting effects of Tides and Currents – Shifting of their position – Differences in the rise of the tides – Causes of currents – Action of the sea on the British coast – Shetland Islands – Large blocks removed – Effects of lightning – Breach caused in a mass of porphyry – Isles reduced to clusters of rocks – Orkney Isles – East coast of Scotland – Stones thrown up on the Bell Rock – East coast of England – Waste of the cliffs of Holderness, Norfolk, and Suffolk – Silting up of Estuaries – Origin of submarine forests – Yarmouth estuary – Submarine forests – Suffolk coast – Dunwich – Essex coast – Estuary of the Thames – Goodwin Sands – Coast of Kent – Formation of Straits of Dover – Coast of Hants – Coast of Dorset – Portland – Origin of the Chesel Bank – Cornwall – Lionnesse tradition – Coast of Brittany
• Chapter 16: Action of Tides and Currents, continued – Inroads of the sea upon the delta of the Rhine in Holland – Changes in the arms of the Rhine – Estuary of the Bies Bosch, formed in 1421 – Formation of the Zuyder Zee, in the 13th century – Islands destroyed – Delta of the Ems converted into a bay – Estuary of the Dollart formed – Encroachment of the sea on the coast of Sleswick – Inroads on the eastern shores of North America – Tidal wave called the Bore – Influence of tides and currents on the mean level of seas – Action of currents on inland lakes and seas – Baltic – Cimbrian deluge – Straits of Gibraltar – Under currents – Shores of Mediterranean – Rocks transported on floating icebergs – Dunes of blown sand – Sands of the Libyan Desert – De Luc's natural chronometers
• Chapter 17: Reproductive effects of Tides and Currents – Silting up of Estuaries does not compensate the loss of land on the borders of the ocean – Bed of the German Ocean – Composition and extent of its sand-banks – Strata formed by currents on the southern and eastern shores of the Mediterranean – Transportation by currents of the sediment of the Amazon, Orinoco, and Mississippi – Stratification – Concluding remarks
• Chapter 18: Division of igneous agents into the volcano and the earthquake – Distinct regions of subterranean disturbance – Region of the Andes – System of volcanos extending from the Aleutian Isles to the Moluccas – Polynesian archipelago – Volcanic region extending from the Caspian Sea to the Azores – Former connexion of the Caspian with Lake Aral and the Sea of Azof – Low steppes skirting these seas – Tradition of deluges on the shores of the Bosphorus, Hellespont, and the Grecian archipelago – Periodical alternation of earthquakes in Syria and Southern Italy – Western limits of the European region – Earthquakes rarer and more feeble in proportion as we recede from the centres of volcanic action – Extinct volcanos not to be included in lines of active vents
• Chapter 19: History of the volcanic eruptions in the district round Naples – Early convulsions in the island of Ischia – Numerous cones thrown up there – Epomeo not an habitual volcano – Lake Avernus – The Solfatara – Renewal of the eruptions of Vesuvius A.D. 79 – Pliny's description of the phenomena – Remarks on his silence respecting the destruction of Herculaneum and Pompeii – Subsequent history of Vesuvius – Lava discharged in Ischia in 1302 – Pause in the eruptions of Vesuvius – Monte Nuovo thrown up – Uniformity of the volcanic operations of Vesuvius and the Phlegraean Fields in ancient and modern times
• Chapter 20: Dimensions and structure of the cone of Vesuvius – Dikes in the recent cone, how formed – Section through Vesuvius and Somma – Vesuvian lavas and minerals – Effects of decomposition of lava – Alluvions called "aqueous lavas" – Origin and composition of the matter enveloping Herculaneum and Pompeii – Controversies on the subject – Condition and contents of the buried cities – Proofs of their having suffered by an earthquake – Small number of skeletons – State of preservation of animal and vegetable substances – Rolls of Papyrus – Probability of future discoveries of MSS. – Stabiae – Torre del Greco – Concluding remarks on the destroying and renovating agency of the Campanian volcanos
• Chapter 21: External physiognomy of Etna – Minor cones produced by lateral eruptions – Successive obliteration of these cones – Early eruptions of Etna – Monti Rossi thrown up in 1669 – Great fissure of S. Lio – Towns overflowed by lava – Part of Catania destroyed – Mode of the advance of a current of lava – Excavation of a church under lava – Series of subterranean caverns – Linear direction of cones formed in 1811 and 1819 – Flood produced in 1755 by the melting of snow during an eruption – A glacier covered by a lava stream on Etna – Volcanic eruptions in Iceland – New island thrown up in 1783 – Two lava-currents of Skaptár Jokul in the same year – Their immense volume – Eruption of Jorullo in Mexico – Humboldt's Theory respecting the convexity of the Plain of Malpais
• Chapter 22: Volcanic Archipelagos – The Canaries – Eruptions of the Peak of Teneriffe – Cones thrown up in Lancerote in 1730-36 – Pretended distinction between ancient and modern lavas – Recent formation of oolitic travertine in Lancerote – Grecian Archipelago – Santorin and its contiguous isles – Von Buch's Theory of "Elevation Craters" considered – New islands thrown up in the Gulf of Santorin – Supposed "Crater of Elevation" in the Isle of Palma – Description of the Caldera of Palma – Barren island in the Bay of Bengal – Origin of the deep gorge on the side of "Elevation Craters" – Stratification of submarine volcanic products – Causes of the great size of the craters of submarine volcanos – Cone of Somma, formed in the same manner as that of Vesuvius – Mineral composition of volcanic products – Speculations respecting the nature of igneous rocks produced at great depths, by modern volcanic eruptions
• Chapter 23: Earthquakes and their effects – Deficiency of ancient accounts – Ordinary atmospheric phenomena – Changes produced by earthquakes in modern times considered in chronological order – Earthquake in Murcia, 1829 – Bogota in 1827 – Chile in 1822 – Great extent of country elevated – Aleppo in 1822 – Ionian Isles in 1820 – Island of Sumbawa in 1815 – Town of Tomboro submerged – Earthquake of Cutch in 1819 – Subsidence of the delta of the Indus – Earthquake of Caraccas in 1812 – South Carolina in 1811 – Geographical changes in the valley of the Mississippi – Volcanic convulsions in the Aleutian Islands in 1806 – Reflections on the earthquakes of the eighteenth century – Earthquake in Quito, 1797 – Cumana, 1797 – Caraccas, 1790 – Sicily, 1790 – Java, 1786 – Sinking down of large tracts
• Chapter 24: Earthquake in Calabria, February 5th, 1783 – Shocks continued to the end of the year 1786 – Authorities – Extent of the area convulsed – Geological structure of the district – Difficulty of ascertaining changes of relative level even on the sea-coast – Subsidence of the quay at Messina – Shift or fault in the Round Tower of Terranuova – Movement in the stones of two obelisks – Alternate opening and closing of fissures – Cause of this phenomenon – Large edifices engulphed – Dimensions of new caverns and fissures – Gradual closing in of rents – Bounding of detached masses into the air – Landslips – Buildings transported entire, to great distances – Formation of fifty new lakes – Currents of mud – Small funnel-shaped hollows in alluvial plains – Fall of cliffs along the sea-coast – Shore near Scilla inundated – State of Stromboli and Etna during the shocks – Illustration afforded by this earthquake of the mode in which valleys are formed
• Chapter 25: Earthquakes of the eighteenth century, continued – Java, 1772 – Truncation of a lofty cone – Caucasus, 1772 – Java, 1771 – Colombia, 1766 – Chile, 1760 – Azores, 1757 – Lisbon, 1755 – Sinking down of the quay to the depth of six hundred feet – Shocks felt throughout Europe, Northern Africa, and the West Indies – Great wave – Shocks felt at sea – St. Domingo, 1751 – Conception Bay, 1750 – Permanent elevation of the bed of the sea to the height of twenty-four feet – Peru, 1746 – Kamtschatka, 1737 – Martinique, 1727. Iceland, 1725 – Teneriffe, 1706 – Java, 1699 – Landslips obstruct the Batas vian and Tangaran rivers – Quito, 1698 – Sicily, 1693 – Subsidence of land – Moluccas,1693 – Jamaica,1692 – Large tracts engulphed – Portion of Port Royal sunk from twenty to fifty feet under water – The Blue Mountains shattered – Reflections on the amount of change in the last one hundred and forty years – Proofs of elevation and subsidence of land on the coast of the Bay of Baise – Evidence of the same afforded by the present state of the Temple of Serapis
• Chapter 26: Magnitude of the subterranean changes produced by earthquakes at great depths below the surface – Obscurity of geological phenomena no proof of want of uniformity in the system, because subterranean processes are but little understood – Reasons for presuming the earthquake and volcano to have a common origin – Probable analogy between the agency of steam in the Icelandic geysers, and in volcanos during eruptions – Effects of hydrostatic pressure of high columns of lava – Of the condensation of vapours in the interior of the earth – That some earthquakes may be abortive eruptions – Why all volcanos are in islands or maritime tracts – Gases evolved from volcanos – Regular discharge of heat and of gaseous and earthy matter from the subterranean regions – Cause of the wave-like motion and of the retreat of the sea during earthquakes – Difference of circumstances of heat and pressure at great depths – Inferences from the superficial changes brought about by earthquakes – In what matter the repair of land destroyed by aqueous causes takes place – Proofs that the sinking in of the earth's crust somewhat exceeds the forcing out by earthquakes – Geological consequences of this hypothesis, that there is no ground for presuming that the degree of force exerted by subterranean movements in a given time has diminished – Concluding remarks
• Index (Part 1)
• Index (Part 2)

Image
ERRATA

LIST OF PLATES AND WOOD-CUTS IN THE FIRST VOLUME.

PLATES.


Frontispiece. -- This representation of the present state of the Temple of Sarapis has been carefully reduced from that given by the Canonico Andrea de Jorio in his 'Ricerche sul Tempio di Serapide, in Puzzuoli.' Napoli, 1820.

Plate l., fig. I. -- Shewing that a chain of volcanic vents surrounds the Asiatic Islands, in the same manner as a continuation of the same line skirts the eastern borders of the continent of Asia. This plate is copied from plate 13 of Von Buch's Phys. Besch. der Canarischen Inseln. Berlin, 1825. The position however of some of the volcanos, and the outline of several of the islands, has been corrected.

Fig. 2. -- Shewing the direction of the trachytic islands from N.W. to S.E. parallel to the principal mountain-chains of Greece, as also to the Grecian islands which constitute a continuation of the mountains of the main-land, and are of the same mineral composition. This plate is also copied from Von Buch, plate 12, p. 318.

Plate 2, fig; I. -- View of the islands of Ischia and Procida, with part of the coast of Misenum, taken from part of plate 17 of Sir W. Hamilton's Campi Phlegraei.

Fig. 2. -- Map of the Volcanic district of Naples. This map is copied from one constructed by G. P. Scrope, Esq., to illustrate a memoir in the Geol. Trans. vol. ii., part 3, from unpublished maps of Captain Smyth, R.N., p. 326.

WOOD-CUTS.

No. PAGE


1. Transverse section of the Italian peninsula, 136

2. Diagram explanatory of the sinuosity of river-courses, 170

3. Diagram shewing the recent excavation of lava at the foot of Etna by the river Simeto, 178

4. Section of travertin of San Vignone, 202

5. Section of spheroidal concretionary travertin seen in descending from the Temple of Vesta, under the Cascade of Tivoli, 209

6. Section on the banks of the Arve at its confluence with the Rhone, shewing the stratification of deposits where currents meet, 254

7. Cut, representing stony fragments drifted by the sea at Northmavine, Shetland, 260

8. View of the 'Grind of the Navir,' a passage forced by the sea through rocks of hard porphyry in the Shetland Isles, 261

9. Granitic rocks named the Drongs, between Papa Stour and Hillswick Ness, Shetland, 262

10. Drongs to the south of Hillswick Ness, Shetland, 263

11. View of Monte Nuovo, formed in the Bay of Baiae, September 29th, 1538, 335

12. View of the volcanos of the Phlegraean Fields, 336

13. Diagram exhibiting a supposed section of Vesuvius and Somma, 344

14. View of Monti Rossi on the flanks of Etsa, formed in 1669, 364

15. Chart and section of Santorin and the contiguous islands in the Grecian Archipelago, 385

16. View of the Isle of Palma, and of the Caldera in its centre, 388

17. View of the cone and crater of Barren Island in the Bay of Bengal, 390

18. Supposed section of the same, 393

19. Deep fissure near Polistena in Calabria caused by the earthquake of 1783, 417

20. Shift or fault in the round tower of Terranuova in Calabria occasioned by the earthquake of 1783, 417

21. Shift in the stones of two obelisks in the Convent of S. Bruno, 418

22. Fissures near Jerocarne in Calabria, caused by the earthquake of 1783, 419

23. Chasm formed by the earthquake near Oppido in Calabria, 420

24. Chasm in the hill of St. Angelo, near Soriano in Calabria caused by the earthquake in 1783, 421

25. Circular pond near Polistena in Calabria caused by the same earthquake, 422

26. Change of the surface at Fra Ramondo, near Soriano in Calabria, 425

27. Landslips near Cinquefrondi caused by earthquake of 1783, 427

28. Circular hollows in the plain of Rosarno formed by the same earthquake, 428

29. Section of one of them, 429

30. Ground plan of the coast of the Bay of Baiae in the environs of Puzzuoli, 450

31. Two sections, the one exhibiting the relation of the recent marine deposits to the more ancient in the Bay of Baiae to the north of Puzzuoli, and the other exhibiting the same relation to the south-east, 450

32. View of the crater of the Great Geyser in Iceland, 464

33. Supposed section of the subterranean reservoir and pipe of a Geyser in Iceland, 464
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Re: Principles of Geology, by Charles Lyell

Postby admin » Fri Jul 17, 2015 12:13 am

CHAPTER 1

Geology defined -- Compared to History -- Its relation to other Physical Sciences -- Its distinctness from all -- Not to be confounded with Cosmogony.

GEOLOGY is the science which investigates the successive changes that have taken place in the organic and inorganic kingdoms of nature; it enquires into the causes of these changes, and the influence which they have exerted in modifying the surface and external structure of our planet.

By these researches into the state of the earth and its inhabitants at former periods, we acquire a more perfect knowledge of its present condition, and more comprehensive views concerning the laws now governing its animate and inanimate productions. When we study history, we obtain a more profound insight into human nature, by instituting a comparison between the present and former states of society. We trace the long series of events which have gradually led to the actual posture of affairs; and by connecting effects with their causes, we are enabled to classify and retain in the memory a multitude of complicated relations -- the various peculiarities of national character -- the different degrees of moral and intellectual refinement, and numerous other circumstances, which, without historical associations, would be uninteresting or imperfectly understood. As the present condition of nations is the result of many antecedent changes, some extremely remote and others recent, some gradual, others sudden and violent, so the state of the natural world is the result of a long succession of events, and if we would enlarge our experience of the present economy of nature, we must investigate the effects of her operations in former epochs.

We often discover with surprise, on looking back into the chronicles of nations, how the fortune of some battle has influenced the fate of millions of our contemporaries, when it has long been forgotten by the mass of the population. With this remote event we may find inseparably connected the geographical boundaries of a great state, the language now spoken by the inhabitants, their peculiar manners, laws, and religious opinions. But far more astonishing and unexpected are the connexions brought to light, when we carry back our researches into the history of nature. The form of a coast, the configuration of the interior of a country, the existence and extent of lakes, valleys, and mountains, can often be traced to the former prevalence of earthquakes and volcanoes, in regions which have long been undisturbed. To these remote convulsions the present fertility of some districts, the sterile character of others, the elevation of land above the sea, the climate, and various peculiarities, may be distinctly referred. On the other hand, many distinguishing features of the surface may often be ascribed to the operation at a remote era of slow and tranquil causes -- to the gradual deposition of sediment in a lake or in the ocean, or to the prolific growth in the same of corals and testacea. To select another example, we find in certain localities subterranean deposits of coal, consisting of vegetable matter, formerly drifted into seas and lakes. These seas and lakes have since been filled up, the lands whereon the forests grew have disappeared or changed their form, the rivers and currents which floated the vegetable masses can no longer be traced, and the plants belonged to species which for ages have passed away from the surface of our planet. Yet the commercial prosperity, and numerical strength of a nation, may now be mainly dependent on the local distribution of fuel determined by that ancient state of things.

Geology is intimately related to almost all the physical sciences, as is history to the moral. An historian should, if possible, be at once profoundly acquainted with ethics, politics, jurisprudence, the military art, theology; in a word, with all branches of knowledge, whereby any insight into human affairs, or into the moral and intellectual nature of man, can be obtained. It would be no less desirable that a geologist should be well versed in chemistry, natural philosophy, mineralogy, zoology, comparative anatomy, botany; in short, in every science relating to organic and inorganic nature. With these accomplishments the historian and geologist would rarely fail to draw correct and philosophical conclusions from the various monuments transmitted to them of former occurrences. They would know to what combination of causes analogous effects were referrible, and they would often be enabled to supply by inference, information concerning many events unrecorded in the defective archives of former ages. But the brief duration of human life, and our limited powers, are so far from permitting us to aspire to such extensive acquisitions, that excellence even in one department is within the reach of few, and those individuals most effectually promote the general progress, who concentrate their thoughts on a limited portion of the field of inquiry. As it is necessary that the historian and the cultivators of moral or political science should reciprocally aid each other, so the geologist and those who study natural history or physics stand in equal need of mutual assistance. A comparative anatomist may derive some accession of knowledge from the bare inspection of the remains of an extinct quadruped, but the relic throws much greater light upon his own science, when he is informed to what relative era it belonged, what plants and animals were its contemporaries, in what degree of latitude it once existed, and other historical details. A fossil shell may interest a conchologist, though he be ignorant of the locality from which it came; but it will be of more value when he learns. with what other species it was associated, whether they were marine or fresh-water, whether the strata containing them were at a certain elevation above the sea, and what relative position they held in regard to other groups of strata, with many other particulars determinable by an experienced geologist alone. On the other hand, the skill of the comparative anatomist and conchologist are often indispensable to those engaged in geological research, although it will rarely happen that the geologist will himself combine these different qualifications in his own person.

Some remains of former organic beings, like the ancient temple, statue, or picture, may have both their intrinsic and their historical value, while there are others which can never be expected to attract attention for their own sake. A painter, sculptor, or architect, would often neglect many curious relics of antiquity, as devoid of beauty and uninstructive with relation to their own art, however illustrative of the progress of refinement in some ancient nation. It has therefore been found desirable that the antiquary should unite his labours to those of the historian, and similar co-operation has become necessary in geology. The field of inquiry in living nature being inexhaustible, the zoologist and botanist can rarely be induced to sacrifice time in exploring the imperfect remains of lost species of animals and plants, while those still existing afford constant matter of novelty. They must entertain a desire of promoting geology by such investigations, and some knowledge of its objects must guide and direct their studies. According to the different opportunities, tastes, and talents of individuals, they may employ themselves in collecting particular kinds of minerals, rocks, or organic remains, and these, when well examined and explained, afford data to the geologist, as do coins, medals, and inscriptions to the historian.

It was long ere the distinct nature and legitimate objects of geology were fully recognized, and it was at first confounded with many other branches of inquiry, just as the limits of history, poetry, and mythology were ill-defined in the infancy of civilization. Werner appears to have regarded geology as little other than a subordinate department of mineralogy, and Desmarest included it under the head of Physical Geography. But the identification of its objects with those of Cosmogony has been the most common and serious source of confusion. The first who endeavoured to draw a clear line of demarcation between these distinct departments, was Hutton, who declared that geology was in no ways concerned "with questions as to the origin of things." But his doctrine on this head was vehemently opposed at first, and although it has gradually gained ground, and will ultimately prevail, it is yet far from being established. We shall attempt in the sequel of this work to demonstrate that geology differs as widely from cosmogony, as speculations concerning the creation of man differ from history. But before we enter more at large on this controverted question, we shall endeavour to trace the progress of opinion on this topic, from the earliest ages, to the commencement of the present century.
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Re: Principles of Geology, by Charles Lyell

Postby admin » Fri Jul 17, 2015 12:14 am

CHAPTER 2

Oriental Cosmogony -- Doctrine of the successive destruction and renovation of the world -- Origin of this doctrine -- Common to the Egyptians -- Adopted by the Greeks -- System of Pythagoras -- Of Aristotle -- Dogmas concerning the extinction and reproduction of genera and species -- Strabo's theory of elevation by earthquakes -- Pliny -- Concluding Remarks on the knowledge of the Ancients.

THE earliest doctrines of the Indian and Egyptian schools of philosophy, agreed in ascribing the first creation of the world to an omnipotent and infinite Being. They concurred also in representing this Being, who had existed from all eternity, as having repeatedly destroyed and reproduced the world and all its inhabitants. In the "Institutes of Menu," the sacred volume of the Hindoos, to which, in its present form, Sir William Jones ascribes an antiquity of at least eight hundred and eighty years before Christ, we find this system of the alternate destruction and renovation of the world, proposed in the following remarkable verses.

"The Being, whose powers are incomprehensible, having created me (Menu) and this universe, again became absorbed in the supreme spirit, changing the time of energy for the hour of repose.

"When that power awakes, then has this world its full expansion; but when he slumbers with a tranquil spirit, then the whole system fades away. .. For while he reposes as it were, embodied spirits endowed with principles of action depart from their several acts, and the mind itself becomes inert."

Menu then describes the absorption of all beings into the Supreme essence, and the Divine soul itself is said to slumber, and to remain for a time immersed in "the first idea, or in darkness." He then proceeds, (verse fifty-seven,) "Thus that immutable power, by waking and reposing alternately, revivifies and destroys, in eternal succession, this whole assemblage of locomotive and immoveable creatures."

It is then declared that there has been a long succession of manwantaras, or periods, each of the duration of many thousand ages, and --

"There are creations also, and destructions of worlds innumerable: the Being, supremely exalted, performs all this with as much ease as if in sport, again and again for the sake of conferring happiness [1]."

The compilation of the ordinances of Menu was not all the work of one author nor of one period, and to this circumstance some of the remarkable inequalities of style and matter are probably attributable. There are many passages, however, wherein the attributes and acts of the "Infinite and Incomprehensible Being" are spoken of with much grandeur of conception and sublimity of diction, as some of the passages above cited, though sufficiently mysterious, may serve to exemplify. There are at the same time such puerile conceits and monstrous absurdities in the same cosmogony, that some may impute to mere accident any slight approximation to truth, or apparent coincidence between the oriental dogmas and observed facts. This pretended revelation, however, was not purely an effort of the unassisted imagination, nor invented without regard to the opinions and observations of naturalists. There are introduced into the same chapter, certain astronomical theories, evidently derived from observation and reasoning. Thus for instance, it is declared that, at the North Pole, the year was divided into a long day and night, and that their long day was the northern, and their night the southern course of the sun; [1] and to the inhabitants of the moon it is said, one day is equal in length to one month of mortals. [2] If such statements cannot be resolved into mere conjectures, we have no right to refer, to mere chance, the prevailing notion, that the earth and its inhabitants had formerly undergone a succession of revolutions and catastrophes, interrupted by long intervals of tranquillity.

Now there are two sources in which such a theory may have originated. The marks of former convulsions on every part of the surface of our planet are obvious and striking. The remains of marine animals imbedded in the solid strata are so abundant, that they may be expected to force themselves on the observation of every people who have made some progress in refinement; and especially where one class of men are expressly set apart from the rest for study and contemplation. If these appearances are once recognized, it seems natural that the mind should come to the conclusion, not only of mighty changes in past ages, but of alternate periods of repose and disorder -- of repose when the fossil animals lived, grew, and multiplied -- of disorder when the strata wherein they were buried became transferred from the sea to the interior of continents, and entered into high mountain chains. Those modern writers, who are disposed to disparage the former intellectual advancement and civilization of eastern nations, might concede some foundation of observed facts for the curious theories now under consideration, without indulging in exaggerated opinions of the progress of science; especially as universal catastrophes of the world, and exterminations of organic beings, in the sense in which they were understood by the Brahmin, are untenable doctrines. We know that the Egyptian priests were aware, not only that the soil beneath the plains of the Nile, but that also the hills bounding the great valley, contained marine shells; and it could hardly have escaped the observation of Eastern philosophers, that some soils were filled with fossil remains, since so many national works were executed on a magnificent scale by oriental monarchs in very remote eras. Great canals and tanks required extensive excavations; and we know that in more recent times (the fourteenth century of our era) the removal of soil necessary for such undertakings, brought to light geological phenomena, which attracted the attention of a people less civilized than were many of the older nations of the East. [3]

But although we believe the Brahmins, like the priests of Egypt, to have been acquainted with the existence of fossil remains in the strata, it is probable that the doctrine of successive destructions and renovations of the world merely received corroboration from such proofs; and that it was originally handed down, like the religious dogmas of most nations, from a ruder state of society. The true source of the system must be sought for in the exaggerated traditions of those partial, but often dreadful catastrophes, which are sometimes occasioned by various combinations of natural causes. Floods and volcanic eruptions, the agency of water and fire, are the chief instruments of devastation on our globe. We shall point out in the sequel the extent of these calamities, recurring at distant intervals of time, in the present course of nature; and shall only observe here, that they are so peculiarly calculated to inspire a lasting terror, and are so often fatal in their consequences to great multitudes of people, that it scarcely requires the passion for the marvellous, so characteristic of rude and half-civilized nations, still less the exuberant imagination of eastern writers, to augment them into general cataclysms and conflagrations.

Humboldt relates the interesting fact, that after the annihilation of a large part of the inhabitants of Cumana, by an earthquake in 1766, a season of extraordinary fertility ensued, in consequence of the great rains which accompanied the subterranean convulsions. "The Indians," he says, "celebrated, after the ideas of an antique superstition, by festivals and dancing, the destruction of the world and the approaching epoch of its regeneration." [4]

The existence of such rites among the rude nations of South America is most important, for it shews what effects may be produced by great catastrophes of this nature, recurring at distant intervals of time, on the minds of a barbarous and uncultivated race. The superstitions of a savage tribe are transmitted through all the progressive stages of society, till they exert a powerful influence on the mind of the philosopher. He may find, in the monuments of former changes on the earth's surface, an apparent confirmation of tenets handed down through successive generations, from the rude hunter, whose terrified imagination drew a false picture of those awful visitations of floods and earthquakes, whereby the whole earth as known to him was simultaneously devastated.

Respecting the cosmogony of the Egyptian priests, we gather much information from writers of the Grecian sects, who borrowed almost all their tenets from Egypt, and amongst others that of the former successive destruction and renovation of the world. [5] We learn from Plutarch, that this was the theme of one of the hymns of Orpheus, so celebrated in the fabulous ages of Greece. It was brought by him from the banks of the Nile; and we even find in his verses, as in the Indian systems, a definite period assigned for the duration of each successive world. [6] The returns of great catastrophes were determined by the period of the Annus Magnus, or great year, a cycle composed of the revolutions of the sun, moon, and planets, and terminating when these return together to the same sign whence they were supposed at some remote epoch to have set out. The duration of this great cycle was variously estimated. According to Orpheus, it was 120,000 years; according to others, 300,000; and by Cassander it was taken to be 360,000 years. [7] We learn particularly from the Timaeus of Plato, that the Egyptians believed the world to be subject to occasional conflagrations and deluges, whereby the gods arrested the career of human wickedness, and purified the earth from guilt. After each regeneration, mankind were in a state of virtue and happiness, from which they gradually degenerated again into vice and immorality. From this Egyptian doctrine, the poets derived the fable of the decline from the golden to the iron age. The sect of Stoics adopted most fully the system of catastrophes destined at certain intervals to destroy the world. These they taught were of two kinds -- the Cataclysm, or destruction by deluge, which sweeps away the whole human race, and annihilates all the animal and vegetable productions of nature; and the Ecpyrosis, or conflagration, which dissolves the globe itself. From the Egyptians also they derived the doctrine of the gradual debasement of man from a state of innocence. Towards the termination of each era the gods could no longer bear with the wickedness of men, and a shock of the elements or a deluge overwhelmed them; after which calamity, Astrea again descended on the earth, to renew the golden age. [8]

The connexion between the doctrine of successive catastrophes and repeated deteriorations in the moral character of the human race, is more intimate and natural than might at first be imagined. For, in a rude state of society, all great calamities are regarded by the people, as judgments of God on the wickedness of man. Thus, in our own time, the priests persuaded a large part of the population of Chili, and perhaps believed themselves, that the great earthquake of 1822 was a sign of the wrath of heaven for the great political revolution just then consummated in South America. In like manner, in the account given to Solon by the Egyptian priests, of the submersion of the island of Atlantis under the waters of the ocean, after repeated shocks of an earthquake, we find that the event happened when Jupiter had seen the moral depravity of the inhabitants. [9] Now, when the notion had once gained ground, whether from causes before suggested or not, that the earth had been destroyed by several general catastrophes, it would next be inferred that the human race had been as often destroyed and renovated. And, since every extermination was assumed to be penal, it could only be reconciled with divine justice, by the supposition that man, at each successive creation, was regenerated in a state of purity and innocence.

A very large portion of Asia, inhabited by the earliest nations whose traditions have come down to us, has been always subject to tremendous earthquakes. Of the geographical boundaries of these, and their effects, we shall, in the proper place, have occasion to speak. Egypt has, for the most part, been exempt from this scourge, and the tradition of catastrophes in that country was perhaps derived from the East.

One extraordinary fiction of the Egyptian mythology was the supposed intervention of a masculo-feminine principle, to which was assigned the development of the embryo world, somewhat in the way of incubation. For the doctrine was, that when the first chaotic mass had been produced, in the form of an egg, by a self-dependent and eternal Being, it required the mysterious functions of this masculo-feminine demi-urgus to reduce the component elements into organized forms. Although it is scarcely possible to recall to mind this conceit without smiling, it does not seem to differ essentially in principle from some cosmological notions of men of great genius and science in modern Europe. The Egyptian philosophers ventured on the perilous task of seeking out some analogy to the mode of operation employed by the Author of Nature in the first creation of organized beings, and they compared it to that which governs the birth of new individuals by generation. To suppose that some general rules might be observed in the first origin of created beings, or the first introduction of new species into our system, was not absurd, nor inconsistent with anything known to us in the economy of the universe. But the hypothesis, that there was any analogy between such laws, and those employed in the continual reproduction of species once created, was purely gratuitous. In like manner, it is not unreasonable or derogatory to the attributes of Omnipotence, to imagine that some general laws may be observed in the creation of new worlds; and if man could witness the birth of such worlds, he might reason by induction upon the origin of his own. But in the absence of such data, an attempt has been made to fancy some analogy between the agents now employed to destroy, renovate, and perpetually vary the earth's surface, and those whereby the first chaotic mass was formed, and brought by supposed nascent energy from the embryo to the habitable state. By how many shades the elaborate systems, constructed on these principles, may differ from the mysteries of the "Mundane Egg" of Egyptian fable, we shall not inquire. It would, perhaps, be dangerous ground, and some of our contemporaries might not sit as patiently as the Athenian audience, when the fiction of the chaotic egg, engrafted by Orpheus upon their own mythology, was turned into ridicule by Aristophanes. That comedian introduced his birds singing, in a solemn hymn, "How sable-plumaged night conceived in the boundless bosom of Erebus, and laid an egg, from which, in the revolution of ages, sprung Love, resplendent with golden pinions. Love fecundated the dark-winged chaos, and gave origin to the race of birds." [10]

Pythagoras, who resided for more than twenty years in Egypt, and, according to Cicero, had visited the East, and conversed with the Persian philosophers, introduced into his own country, on his return, the doctrine of the gradual deterioration of the human race from an original state of virtue and happiness; but if we are to judge of his theory concerning the destruction and renovation of the earth, from the sketch given by Ovid, we must concede it to have been far more philosophical than any known version of the cosmologies of Oriental or Egyptian sects. Although Pythagoras is introduced by the poet as delivering his doctrine in person, some of the illustrations are derived from natural events which happened after the death of the philosopher. But notwithstanding these anachronisms, we may regard the account as a true picture of the tenets of the Pythagorean school in the Augustan age; and although perhaps partially modified, it must have contained the substance of the original scheme. Thus considered, it is extremely curious and instructive; for we here find a comprehensive and masterly summary of almost all the great causes of change now in activity on the globe, and these adduced in confirmation of a principle of perpetual and gradual revolution inherent in the nature of our terrestrial system. These doctrines, it is true, are not directly applied to the explanation of geological phenomena; or, in other words, no attempt is made to estimate what may have been, in past ages, or what may hereafter be, the aggregate amount of change brought about by such never-ending fluctuations. Had this been the case, we might have been called upon to admire so extraordinary an anticipation with no less interest than astronomers, when they endeavour to divine by what means the Samian philosopher came to the knowledge of the Copernican theory. Let us now examine the celebrated passages to which we have been adverting: -- [11]

"Nothing perishes in this world; but things merely vary and change their form. To be born, means simply that a thing begins to be something different from what it was before; and dying, is ceasing to be the same thing. Yet, although nothing retains long the same image, the sum of the whole remains constant." These general propositions are then confirmed by a series of examples, all derived from natural appearances, except the first, which refers to the golden age giving place to the age of iron. The illustrations are thus consecutively adduced.

1. Solid land has been converted into sea.

2. Sea has been changed into land. Marine shells lie far distant from the deep, and the anchor has been found on the summit of hills.

3. Valleys have been excavated by running water, and floods have washed down hills into the sea. [12]

4. Marshes have become dry ground.

5. Dry lands have been changed into stagnant pools.

6. During earthquakes some springs have been closed up, and new ones have broken out. Rivers have deserted their channels, and have been re-born elsewhere; as the Erasinus in Greece, and Mysus in Asia.

7. The waters of some rivers, formerly sweet, have become bitter, as those of the Anigris in Greece, &c. [13]

8. Islands have become connected with the main land by the growth of deltas and new deposits, as in the case of Antissa joined to Lesbos, Pharos to Egypt, &c.

9. Peninsulas have been divided from the main land, and have become islands, as Leucadia; and according to tradition Sicily, the sea having carried away the isthmus.

10. Land has been submerged by earthquakes: the Grecian cities of Helice and Buris, for example, are to be seen under the sea, with their walls inclined.

11. Plains have been upheaved into hills by the confined air seeking vent, as at Trrezen in the Peloponnese.

12. The temperature of some springs varies at different periods.

13. The waters of others are inflammable. [14]

14. Extraordinary medicinal and deleterious effects are produced by the water of different lakes and springs. [15]

15. Some rocks and islands, after floating, and having been subject to violent movements, have at length become stationary and immoveable, as Delos and the Cyanean Isles. [16]

16. Volcanic vents shift their position; there was a time when Etna was not a burning mountain, and the time will come when it will cease to burn. Whether it be that some caverns become closed up by the movements of the earth, and others opened, or whether the fuel is finally exhausted, &c. &c.

The various causes of change in the inanimate world having been thus enumerated, the doctrine of equivocal generation is next propounded, as illustrating a corresponding perpetual flux in the animate creation. [17]

In the Egyptian and Eastern cosmogonies, and in the Greek version of them, no very definite meaning can, in general, be attached to the term "destruction of the world," for sometimes it would seem almost to imply the annihilation of our planetary system, and at others a mere revolution of the surface of the earth.

From the works now extant of Aristotle, and from the system of Pythagoras, as above exposed, we might certainly infer that these philosophers considered the agents of change now operating in Nature, as capable of bringing about in the lapse of ages a complete revolution; and the Stagyrite even considers occasional catastrophes, happening at distant intervals of time, as part of the regular and ordinary course of Nature. The deluge of Deucalion, he says, affected Greece only, and principally the part called Hellas, and it arose from great inundations of rivers during a rainy winter. But such extraordinary winters, he says, though after a certain period they return, do not always revisit the same places. [18] Censorinus quotes it as Aristotle's opinion, that there were general inundations of the globe, and that they alternated with conflagrations, and that the flood constituted the winter of the great year, or astronomical cycle, while the conflagration, or destruction by fire, is the summer or period of greatest heat. [19] If this passage, as Lipsius supposes, be an amplification by Censorinus, of what is written in "the Meteorics," it is a gross misrepresentation of the doctrine of the Stagyrite, for the general bearing of his reasoning in that treatise tends clearly in an opposite direction. He refers to many examples of changes now constantly going on, and insists emphatically on the great results which they must produce in the lapse of ages. He instances particular cases of lakes that had dried up, and deserts that had at length become watered by rivers and fertilized. He points to the growth of the Nilotic delta since the time of Homer, to the shallowing of the Palus Maeotis within sixty years from his own time, and although, in the same chapter, he says nothing of earthquakes, yet in others of the same treatise, [20] he shews himself not unacquainted with their effects.

He alludes, for example, to the upheaving of one of the Eolian islands, previous to a volcanic eruption. "The changes of the earth, he says, are so slow in comparison to the duration of our lives, that they are overlooked (Image); and the migrations of people after great catastrophes, and their removal to other regions, cause the event to be forgotten." [21] When we consider the acquaintance displayed by Aristotle with the destroying and renovating powers of nature in his various works, the introductory and concluding passages of the twelfth chapter of his "Meteorics" are certainly very remarkable. In the first sentence he says, "the distribution of land and sea in particular regions does not endure throughout all time, but it becomes sea in those parts where it was land, and again it becomes land where it was sea, and there is reason for thinking that these changes take place according to a certain system, and within a certain period." The concluding observation is as follows: "As time never fails, and the universe is eternal, neither the Tanais, nor the Nile, can have flowed for ever. The places where they rise were once dry, and there is a limit to their operations, but there is none to time. So also of all other rivers, they spring up and they perish, and the sea also continually deserts some lands and invades others. The same tracts, therefore, of the earth are not some always sea, and others always continents, but every thing changes in the course of time."

It seems, then, that the Greeks had not only derived from preceding nations, but had also, in some degree, deduced from their own observations, the theory of great periodical revolutions in the inorganic world, but there is no ground for imagining that they contemplated former changes in the races of animals and plants. Even the fact, that marine remains were inclosed in solid rocks, although observed by many, and even made the groundwork of geological speculation, never stimulated the industry or guided the inquiries of naturalists. It is not impossible that the theory of equivocal generation might have engendered some indifference on this subject, and that a belief in the spontaneous production of living beings from the earth, or corrupt matter, might have caused the organic world to appear so unstable and fluctuating, that phenomena indicative of former changes would not awaken intense curiosity. The Egyptians, it is true, had taught, and the Stoics had repeated, that the earth had once given birth to some monstrous animals, which existed no longer; but the prevailing opinion seems to have been, that after each great catastrophe the same species of animals were created over again. This tenet is implied in a passage of Seneca, where, speaking of a future deluge, he says, "Every animal shall be generated anew, and men free from guilt shall be given to the earth." [22] An old Arabian version of the doctrine of the successive revolutions of the globe, translated by Abraham Ecchellensis, [23] seems to form a singular exception to the general rule, for here we find the idea of different genera and species having been created. The Gerbanites, a sect of astronomers who flourished some centuries before the Christian era, taught as follows: -- "That after every period of thirty-six thousand years, there were produced twenty-five pair of every species of animals, male and female, from whom animals might be propagated and inhabit this lower world. But when a circulation of the heavenly orbs was completed, which is finished in that space of years, other genera and species of animals are propagated, as also of plants and other things, and the first order is destroyed, and so it goes on for ever and ever." [24]

As we learn much of the tenets of the Egyptian and Oriental schools in the writings of the Greeks, so many speculations of the early Greek authors are made known to us in the works of the Augustan and later ages. Strabo, in particular, enters largely, in the Second Book of his Geography, into the opinions of Eratosthenes and other Greeks on one of the most difficult problems in geology, viz., by what causes marine shells came to be plentifully buried in the earth at such great elevations and distances from the sea. He notices, amongst others the explanation of Xanthus the Lydian, who said that the seas had once been more extensive, and that they had afterwards been partially dried up, as in his own time many lakes, rivers, and wells in Asia had failed during a season of drought. Treating this conjecture with merited disregard, Strabo passes on to the hypothesis of Strato, the natural philosopher, who had observed that the quantity of mud brought down by rivers into the Euxine was so great, that its bed must be gradually raised, while the rivers still continued to pour in an undiminished quantity of water. He therefore conceived, that, originally, when the Euxine was an inland sea, its level had by this means become so much elevated that it burst its barrier near Byzantium, and formed a communication with the Propontis, and this partial drainage had already, he supposed, converted the left side into marshy ground, and that, at last, the whole would be choked up with soil. So, it was argued, the Mediterranean had once opened a passage for itself by the Columns of Hercules into the Atlantic, and perhaps the abundance of seashells in Africa, near the Temple of Jupiter Ammon, might also be the deposit of some former inland sea, which had at length forced a passage and escaped. But Strabo rejects this theory as insufficient to account for all the phenomena, and he proposes one of his own, the profoundness of which modern geologists are only beginning to appreciate. "It is not," he says, "because the lands covered by seas were originally at different altitudes, that the waters have risen, or subsided, or receded from some parts and inundated others. But the reason is, that the same land is sometimes raised up and sometimes depressed, and the sea also is simultaneously raised and depressed, so that it either overflows, or returns into its own place again. We must therefore ascribe the cause to the ground, either to that ground which is under the sea, or to that which becomes flooded by it, but rather to that which lies beneath the sea, for this is more moveable, and, on account of its humidity, can be altered with greater celerity. [25] "It is proper," he observes in continuation, "to derive our explanations from things which are obvious, and in some measure of daily occurrence, such as deluges, earthquakes, volcanic eruptions, and sudden swellings of the land beneath the sea; for the last raise up the sea also, and when the same lands subside again, they occasion the sea to be let down. And it is not merely the small, but the large islands also, and not merely the islands but the continents which can be lifted up together with the sea; and both large and small tracts may subside, for habitations and cities, like Bure Bizona, and many others, have been engulfed by earthquakes." In another place, this learned geographer, in alluding to the tradition that Sicily had been separated by a convulsion from Italy, remarks, that at present the land near the sea in those parts was rarely shaken by earthquakes, since there were now open orifices whereby fire and ignited matters and waters escaped; but formerly, when the volcanoes of Etna, the Lipari Islands, Ischia, and others, were closed up, the imprisoned fire and wind might have produced far more vehement movements. [26] The doctrine, therefore, that volcanoes are safety-valves, and that the subterranean convulsions are probably most violent when first the volcanic energy shifts itself to a new quarter, is not modern.

We learn from a passage in Strabo, [27] that it was a dogma of the Gaulish Druids that the universe was immortal, but destined to survive catastrophes both of fire and water. That this doctrine was communicated to them from the East, with much of their learning, cannot be doubted. Caesar, [28] it will be remembered, says, that they made use of Greek letters in arithmetical computations.

Pliny had no theoretical opinions of his own, concerning changes of the earth's surface; and in this department, as in others, he restricted himself to the task of a compiler, without reasoning on the facts stated by him, or attempting to digest them into regular order. His enumeration of the new islands which had been formed in the Mediterranean, and of other convulsions, shew that the ancients had not been inattentive observers of the changes which had taken place on the earth within the memory of man.

We shall now conclude our remarks on the opinions entertained before the Christian era, concerning the past revolutions of our globe. No particular investigations appear to have been made for the express purpose of interpreting the monuments left by nature of ancient changes, but they were too obvious to be entirely disregarded; and the observation of the present course of nature presented too many proofs of alterations continually in progress on the earth to allow philosophers to believe that nature was in a state of rest, or that the surface had remained, and would continue to remain, unaltered. But they had never compared attentively the results of the destroying and reproductive operations of modern times with those of remote eras, nor had they ever entertained so much as a conjecture concerning the comparative antiquity of the human race, and living species of animals and plants, with those belonging to former conditions of the organic world. They had studied the movements and positions of the heavenly bodies with laborious industry, and made some progress in investigating the animal, vegetable, and mineral kingdoms; but the ancient history of the globe was to them a sealed book, and, although written in characters of the most striking and imposing kind, they were unconscious even of its existence.

_______________

Notes:

1. Institutes of Hindoo Law, or the Ordinances of Menu, from the Sanscrit, translated by Sir William Jones, 1796.

2. Menu Instit. c. i. 66 and 67.

3. This circumstance is mentioned in a Persian MS. copy of the historian Ferishta, in the library of the East India Company, relating to the rise and progress of the Mahomedan Empire in India, and procured from the library of Tippoo Sultaun in 1799; and has been recently referred to at some length by Dr. Buckland. -- (Geol. Trans. 2d Series, vol. ii. part iii. p. 389.) -- It is stated that, in the year 762, (or 1360 of our era) the king employed fifty thousand labourers in cutting through a mound, so as to form a junction between the rivers Selima and Sutluj, and in this mound were found the bones of elephants and men, some of them petrified, and some of them resembling bone. The gigantic dimensions attributed to the human bones shew them to have belonged to some of the larger pachydermata.

4. Humboldt et Bonpland, Voy. Relat. Hist. vol. i. p. 30.

5. Prichard's Egypt. Mythol. p. 177.

6. Pluto de Defectu Oraculorum, cap. 12. Censorinus de die Nat. See also Prichard's Egypt. Mythol. p. 183.

7. Prichard's Egypt. Mythol. p. 182.

8. Prichard's Egypt. Mythol. p. 193.

9. Plato's Timoeus.

10. Aristophanes' Birds, 694.

11. Ovid's Metamor. lib. 15.

12. Eluvie mons est deductus in oequor, v. 267. The meaning of this last verse is somewhat obscure, but taken with the context, may be supposed to allude to the abrading power of floods, torrents, and rivers.

13. The impregnation from new mineral springs, caused by earthquakes in volcanic countries, is, perhaps, here alluded to.

14. This is probably an allusion to the escape of inflammable gas, like that in the district of Baku, west of the Caspian; at Pietra-mala, in the Tuscan Apennines; and several other places.

15. Many of those described seem fanciful fictions, like the virtues still so commonly attributed to mineral waters.

16. Raspe, in a learned and judicious essay (chap. 19, de novis insulis), has made it appear extremely probable that all the traditions of certain islands in the Mediterranean having at some former time frequently shifted their position, and at length become stationary, originated in the great change produced in their form by earthquakes and submarine eruptions, of which there have been modern examples in the new islands raised in the time of history. When the series of convulsions ended, the island was said to become fixed.

17. It is not inconsistent with the Hindoo mythology to suppose, that Pythagoras might have found in the East not only the system of universal and violent catastrophes and periods of repose in endless succession, but also that of periodical revolutions, effected by the continued agency of ordinary causes. For Brahma, Vishnu, and Siva, the first, second, and third persons of the Hindoo triad, severally represented the Creative, the Preserving, and the Destroying powers of the Deity. The co-existence of these three attributes, all in simultaneous operation, might well accord with the notion of perpetual but partial alterations finally bringing about a complete change. But the fiction expressed in the verses before quoted from Menu, of eternal vicissitudes in the vigils and slumbers of the Infinite Being seems accommodated to the system of great general catastrophes followed by new creations and periods of repose.

18. Meteor. lib. i. cap. xii.

19. De Die. Nat.

20. Lib. ii. cap. 14, 15, and 16.

21. Lib. ii. cap. 14, 15, and 16.

22. Omne ex integro animal generabitur, dabiturque terris homo inscius scelerum. Quest. Nat. iii. c. 29.

23. This author was Regius Professor of Syriac and Arabic at Paris, where, in 1685, he published a Latin translation of many Arabian MSS. on different departments of philosophy. This work has always been considered of high authority.

24. Gerbanitae docebant singulos triginta sex mille annos quadringentos, viginti quinque bina ex singulis animalium speciebus produci, marem scilicet ac feminam, ex quibus animalia propagantur, huncque inferiorem incolunt orbem. Absoluta autem coelestium orbium circulatione, quae illo annorum conficitur spatio, iterum alia producuntur animalium genera et species, quemadmodum et plantarum aliarumque rerum, et primus destruitur ordo, sicque in infinitum producitur. -- Histor. Orient. Suppl. per Abrahamum Ecchellensum, Syrum Maronitam, cap. 7 et 8. ad calcem Chronici Oriental. Parisiis, e Typ. regia 1685. fol.

Fortis fell into a singular mistake in rendering this passage, imagining that the number twenty-five referred not to the pairs of every animal created, but to the number of new species created at one time; and hence the doctrine of the Arabian sect appeared to coincide somewhat with his own views; and, to be consistent with his hypothesis, that man and some species of animals and plants are more modern than others. -- Fortis, Mem. sur l'Hist. Nat. de l'Italie, vol. i. p. 202.

25. "Quod enim hoc attollitur aut subsidit, et vel inundat quaedam loca, vel ab iis recedit, ejus rei causa non est, quod alia aliis sola humiliora sint aut altiora; sed quod idem solum modo attollitur modo deprimitur, simulque etiam modo attollitur modo deprimitur mare: itaque vel exundat vel in suum redit locum."

Postea, p. 88. "Restat, ut causam adscribamus solo, sive quod mari subest sive quod inundatur; potius tamen ei quod mari subest. Hoc enim multo est mobilius et quod ob humiditatem celerius mutari possit." -- Strabo, lib. ii.

26. Strabo, lib. vi. p. 396.

27. Book iv.

28. 1. vi. ch. 13.
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Re: Principles of Geology, by Charles Lyell

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PART 1 OF 2

CHAPTER 3

Arabian writers of the Tenth century -- Persecution of Omar -- Cosmogony of the Koran -- Early Italian writers -- Fracastoro -- Controversy as to the real nature of organized fossils -- Fossil shells attributed to the Mosaic deluge -- Palissy -- Steno -- Scilla -- Quirini -- Boyle -- Plot -- Hooke's Theory of Elevation by earthquakes -- His speculations on lost species of animals -- Ray -- Physicotheological writers -- Woodward's Diluvial Theory -- Burnet -- Whiston -- Hutchinson -- Leibnitz -- Vallisneri -- Lazzoro Moro -- Generelli -- Buffon -- His theory condemned by the Sorbonne as unorthodox -- Buffon's declaration -- Targioni -- Arduino -- Michell -- Catcott -- Raspe -- Fortis -- Testa -- Whitehurst -- Pallas -- Saussure.

AFTER the decline of the Roman empire, the cultivation of physical science was first revived with some success by the Saracens, about the middle of the eighth century of our era. The works of the most eminent classic writers were purchased at great expense from the Christians, and translated into Arabic; and Al Mamum, son of the famous Harun-al-Rashid, the contemporary of Charlemagne, received with marks of distinction, at his court at Bagdad, astronomers and men of learning from different countries. This caliph, and some of his successors, encountered much opposition and jealousy from the doctors of the Mahomedan law, who wished the Moslems to confine their studies to the Koran, dreading the effects of the diffusion of a taste for the physical sciences. [1] Almost all the works of the early Arabian writers are lost. Amongst those of the tenth century, of which fragments are now extant, is a system of mineralogy by Avicenna, a physician, in whose arrangement there is considerable merit. In the same century also, Omar, surnamed "El Aalem," or "the Learned," wrote a work on "the Retreat of the Sea." It appears that on comparing the charts of his own time with those made by the Indian and Persian astronomers two thousand years before, he had satisfied himself that important changes had taken place since the times of history in the form of the coasts of Asia, and that the extension of the sea had been greater at some former periods. He was confirmed in this opinion by the numerous salt springs and marshes in the interior of Asia; a phenomenon from which Pallas, in more recent times, has drawn the same inference.

Von Hoff has suggested, with great probability, that the changes in the level of the Caspian, (some of which there is reason to believe have happened within the historical era,) and the geological appearances in that district, indicating the desertion by that sea of its ancient bed, had probably led Omar to his theory of a general subsidence. But whatever may have been the proofs relied on, his system was declared contradictory to certain passages in the Koran, and he was called upon publicly to recant his errors; to avoid which persecution he went into voluntary banishment from Samarkand. [2]

The cosmological opinions expressed in the Koran are few, and merely introduced incidentally; so that it is not easy to understand how they could have interfered so seriously with free discussion on the former changes of the globe. The Prophet declared that the earth was created in two days, and the mountains were then placed on it; and during these, and two additional days, the inhabitants of the earth were formed; and in two more the seven heavens. [3] There is no more detail of circumstances; and the deluge, which is also mentioned, is discussed with equal brevity. The waters are represented to have poured out of an oven; a strange fable, said to be borrowed from the Persian Magi, who represented them as issuing from the oven of an old woman. [4] All men were drowned, save Noah and his family; and then God said, "O earth, swallow up thy waters; and thou, O heaven, withhold thy rain;" and immediately the waters abated. [5]

We may suppose Omar to have represented the desertion of the land by the sea to have been gradual, and that his hypothesis required a greater lapse of ages than was consistent with Moslem orthodoxy; for it is to be inferred from the Koran, that man and this planet were created at the same time; and although Mahomet did not limit expressly the antiquity of the human race, yet he gave an implied sanction to the Mosaic chronology by the veneration expressed by him for the Hebrew Patriarchs. [6]

We must now pass over an interval of five centuries, wherein darkness enveloped almost every department of science, and buried in profound oblivion all prior investigations into the earth's history and structure. It was not till the earlier part of the sixteenth century that geological phenomena began to attract the attention of the Christian nations. At that period a very animated controversy sprung up in Italy, concerning the true nature and origin of marine shells, and other organized fossils, found abundantly in the strata of the peninsula. [7] The excavations made in 1517, for repairing the city of Verona, brought to light a multitude of curious petrifactions, and furnished matter for speculation to different authors, and among the rest to Fracastoro, [8] who declared his opinion, that fossil shells had all belonged to living animals, which had formerly lived and multiplied, where their exuviae are now found. He exposed the absurdity of having recourse to a certain "plastic force," which it was said had power to fashion stones into organic forms; and, with no less cogent arguments, demonstrated the futility of attributing the situation of the shells in question to the Mosaic deluge, a theory obstinately defended by some. That inundation, he observed, was too transient, it consisted principally of fluviatile waters; and, if it had transported shells to great distances, must have strewed them over the surface, not buried them at vast depths in the interior of mountains. His clear exposition of the evidence would have terminated the discussion for ever; if the passions of mankind had not been enlisted in the dispute; and even though doubts should for a time have remained in some minds, they would speedily have been removed by the fresh information obtained almost immediately afterwards, respecting the structure of fossil remains, and of their living analogues. But the clear and philosophical views of Fracastoro were disregarded, and the talent and argumentative powers of the learned were doomed for three centuries to be wasted in the discussion of these two simple and preliminary questions: first, whether fossil remains had ever belonged to living creatures; and, secondly, whether, if this be admitted, all the phenomena could be explained by the Noachian deluge. It had been the consistent belief of the Christian world, down to the period now under consideration, that the origin of this planet was not more remote than a few thousand years; and that since the creation the deluge was the only great catastrophe by which considerable change had been wrought on the earth's surface. On the other hand, the opinion was scarcely less general, that the final dissolution of our system was an event to be looked for at no distant period. The era, it is true, of the expected millennium had passed away; and for five hundred years after the fatal hour, when the annihilation of the planet had been looked for, the monks remained in undisturbed enjoyment of rich grants of land bequeathed to them by pious donors, who, in the preamble of deeds beginning "appropinquante mundi termino"--"appropinquante magno judicii die," [As the end of the world is now at hand.] [9] left lasting monuments of the popular delusion.

But although in the sixteenth century it had become necessary to interpret the prophecies more liberally, and to assign a more distant date to the future conflagration of the world, we find, in the speculations of the early geologists, perpetual allusion to such an approaching catastrophe; while, in all that regarded the antiquity of the earth, no modification whatever of the opinions of the dark ages had been effected. Considerable alarm was at first excited when the attempt was made to invalidate by physical proofs an article of faith so generally received, but there was sufficient spirit of toleration and candour amongst the Italian ecclesiastics, to allow the subject to be canvassed with much freedom. They entered warmly themselves into the controversy, often favouring different sides of the question; and however much we may deplore the loss of time and labour devoted to the defence of untenable positions, it must be conceded, that they displayed far less polemic bitterness than certain writers who followed them "beyond the Alps," two centuries and a half later.

The system of scholastic disputations encouraged in the Universities of the middle ages had unfortunately trained men to habits of indefinite argumentation, and they often preferred absurd and extravagant propositions, because greater skill was required to maintain them; the end and object of such intellectual combats being victory and not truth. No theory could be too far-fetched or fantastical not to attract some followers, provided it fell in with popular notions; and as cosmologists were not at all restricted, in building their systems, to the agency of known causes, the opponents of Fracastoro met his arguments by feigning imaginary causes, which differed from each other rather in name than in substance. Andrea Mattioli, for instance, an eminent botanist, the illustrator of Dioscorides, embraced the notion of Agricola, a German miner, that a certain "materia pinguis" or "fatty matter," set into fermentation by heat, gave birth to fossil organic shapes. Yet Mattioli had come to the conclusion from his own observations, that porous bodies, such as bones and shells, might be converted into stone, as being permeable to what he termed the "lapidifying juice." In like manner, Falloppio of Padua conceived that petrified shells had been generated by fermentation in the spots where they were found, or that they had in some cases acquired their form from "the tumultuous movements of terrestrial exhalations." Although not an unskilful professor of anatomy, he taught that certain tusks of elephants dug up in his time at Puglia were mere earthy concretions, and, consistently with these principles, he even went so far as to consider it not improbable, that the vases of Monte Testaceo at Rome were natural impressions stamped in the soil. [10] In the same spirit, Mercati, who published, in 1574, faithful figures of the fossil shells preserved by Pope Sextus V. in the Museum of the Vatican, expressed an opinion that they were mere stones, which had assumed their peculiar configuration from the influence of the heavenly bodies; and Olivi of Cremona, who described the fossil remains of a rich Museum at Verona, was satisfied with considering them mere "sports of nature."

The title of a work of Cardano's, published in 1552, "De Subtilitate," (corresponding to what would now be called, Transcendental Philosophy,) would lead us to expect in the chapter on minerals, many far-fetched theories characteristic of that age; but, when treating of petrified shells, he decided that they clearly indicated the former sojourn of the sea upon the mountains. [11]

Some of the fanciful notions of those times were deemed less unreasonable, as being somewhat in harmony with the Aristotelian theory of spontaneous generation, then taught in all the schools. For men who had been instructed in early youth, that a large proportion of living animals and plants were formed from the fortuitous concourse of atoms, or had sprung from the corruption of organic matter, might easily persuade themselves, that organic shapes, often imperfectly preserved in the interior of solid rocks, owed their existence to causes equally obscure and mysterious.

But there were not wanting some, who at the close of this century expressed more sound and sober opinions. Cesalpino, a celebrated botanist, conceived that fossil shells had been left on the land by the retiring sea, and had concreted into stone during the consolidation of the soil; [12] and in the following year (1597), Simeone Majoli [13] went still further, and, coinciding for the most part with the views of Cesalpino, suggested that the shells and submarine matter of the Veronese, and other districts, might have been cast up, upon the land, by volcanic explosions, like those which gave rise, in 1588, to Monte Nuovo, near Puzzuoli. -- This hint was the first imperfect attempt to connect the position of fossil shells with the agency of volcanoes, a system afterwards more fully developed by Hooke, Lazzoro Moro, Hutton, and other writers.

Two years afterwards, Imperati advocated the animal origin of fossilized shells, yet admitted that stones could vegetate by force of "an internal principle;" and, as evidence of this, he referred to the teeth of fish, and spines of echini found petrified. [14]

Palissy, a French writer on "the Origin of Springs from Rain-water" and of other scientific works, undertook, in 1580, to combat the notions of many of his contemporaries in Italy, that petrified shells had all been deposited by the universal deluge. "He was the first," said Fontenelle, when, in the French Academy, he pronounced his eulogy more than fifty years afterwards, "who dared assert" in Paris, that fossil remains of testacea and fish had once belonged to marine animals.

To enumerate the multitude of Italian writers, who advanced various hypotheses, all equally fantastical, in the early part of the seventeenth century, would be unprofitably tedious, but Fabio Colonna deserves to be distinguished; for, although he gave way to the dogma, that all fossil remains were to be referred to the Noachian deluge, he resisted the absurd theory of Stelluti, who taught that fossil wood and ammonites were mere clay, altered into such forms by sulphureous waters and subterranean heat; and he pointed out the different states of shells buried in the strata, distinguishing between, first, the mere mould or impression; secondly, the cast or nucleus; and thirdly, the remains of the shell itself. He had also the merit of being the first to point out, that some of the fossils had belonged to marine, and some to terrestrial testacea. [15] But the most remarkable work of that period was published by Steno, a Dane, once professor of anatomy at Padua, and who afterwards resided many years at the court of the Grand Duke of Tuscany. The treatise bears the quaint title of "De Solido intra Solidum contento naturaliter, (1669,)" by which the author intended to express "On Gems, Crystals, and organic Petrifactions inclosed within solid Rocks." This work attests the priority of the Italian school in geological research; exemplifying at the same time the powerful obstacles opposed, in that age, to the general reception of enlarged views in the science. Steno had compared the fossil shells with their recent analogues, and traced the various gradations from the state of mere calcination, when their natural gluten only was lost, to the perfect substitution of stony matter. He demonstrated that many fossil teeth found in Tuscany belonged to a species of shark; and he dissected, for the purpose of comparison, one of these fish recently taken from the Mediterranean. That the remains of shells and marine animals found petrified were not of animal origin was still a favourite dogma of many who were unwilling to believe, that the earth could have been inhabited by living beings, long before many of the mountains were formed. By way of compromise, as it were, for dissenting from this opinion, Steno conceded, as Fabio Colonna had done before him, that all marine fossils might have been transported into their present situation at the time of the Noachian deluge. He maintained that fossil vegetables had been once living plants, and he hinted that they might, in some instances, indicate the distinction between fluviatile and marine deposits. He also inferred that the present mountains had not existed ever since the origin of things, suggesting that many strata of submarine origin had been accumulated in the interval between the creation and deluge. Here he displayed his great anxiety to reconcile his theory with the Scriptures; for he at the same time advanced an opinion, which does not seem very consistent with such a doctrine, viz. that there was a wide distinction between the shelly, and nearly horizontal beds at the foot of the Apennines, and the older mountains of highly inclined stratification. Both, he observed, were of sedimentary origin; and a considerable interval of time must have separated their formation. Tuscany, according to him, had successively past through six different states; and to explain these mighty changes, he called in the agency of inundations, earthquakes, and subterranean fires.

His generalizations were for the most part comprehensive and just; but such was his awe of popular prejudice, that he only ventured to throw them out as mere conjectures, and the timid reserve of his expressions must have raised doubts as to his own confidence in his opinions, and deprived them of some of the authority due to them.

Scilla, a Sicilian painter, published, in 1670, a work on the fossils of Calabria, illustrated by good engravings. This was written in Latin, with great spirit and elegance, and it proves the continued ascendancy of dogmas often refuted; for we find the wit and eloquence of the author chiefly directed against the obstinate incredulity of naturalists, as to the organic nature of fossil shells. [16] Like many eminent naturalists of his day, Scilla gave way to the popular persuasion that all fossil shells were the effects and proofs of the Mosaic deluge. It may be doubted whether he was perfectly sincere, and some of his contemporaries who took the same course were certainly not so. But so eager were they to root out what they justly considered an absurd prejudice respecting the nature of organized fossils, that they seem to have been ready to make any concessions, in order to establish this preliminary point. Such a compromising policy was short-sighted, since it was to little purpose that the nature of the documents should at length be correctly understood, if men were to be prevented from deducing fair conclusions from them.

The theologians who now entered the field in Italy, Germany, France and England, were innumerable; and henceforward, they who refused to subscribe to the position, that all marine organic remains were proofs of the Mosaic deluge, were exposed to the imputation of disbelieving the whole of the sacred writings. Scarcely any step had been made in approximating to sound theories since the time of Fracastoro, more than a hundred years having been lost, in writing down the dogma that organized fossils were mere sports of nature. An additional period of a century and a half was now destined to be consumed in exploding the hypothesis, that organized fossils had all been buried in the solid strata, by the Noachian flood. Never did a theoretical fallacy, in any branch of science, interfere more seriously with accurate observation and the systematic classification of facts. In recent times, we may attribute our rapid progress chiefly to the careful determination of the order of succession in mineral masses, by means of their different organic contents, and their regular superposition. But the old diluvialists were induced by their system to confound all the groups of strata together instead of discriminating, -- to refer all appearances to one cause and to one brief period, not to a variety of causes acting throughout a long succession of epochs. They saw the phenomena only as they desired to see them, sometimes misrepresenting facts, and at other times deducing false conclusions from correct data. Under the influence of such prejudices, three centuries were of as little avail, as the same number of years in our own times, when we are no longer required to propel the vessel against the force of an adverse current.

It may be well to forewarn our readers, that in tracing the history of geology from the close of the seventeenth to the end of the eighteenth century, they must expect to be occupied with accounts of the retardation, as well as of the advance of the science. It will be our irksome task to point out the frequent revival of exploded errors, and the relapse from sound to the most absurd opinions. It will be necessary to dwell on futile reasoning and visionary hypothesis, because the most extravagant systems were often invented or controverted by men of acknowledged talent. A sketch of the progress of Geology is the history of a constant and violent struggle between new opinions and ancient doctrines, sanctioned by the implicit faith of many generations, and supposed to rest on scriptural authority. The inquiry, therefore, although highly interesting to one who studies the philosophy of the human mind, is singularly barren of instruction to him who searches for truths in physical science.

Quirini, in 1676, [17] contended, in opposition to Scilla, that the diluvian waters could not have conveyed heavy bodies to the summit of mountains, since the agitation of the sea never (as Boyle had demonstrated) extended to great depths, [18] and still less could the testacea, as some pretended, have lived in these diluvial waters, for "the duration of the flood was brief, and the heavy rains must have destroyed the saltness of the sea!" He was the first writer who ventured to maintain that the universality of the Noachian cataclysm ought not to be insisted upon. As to the nature of petrified shells, he conceived that as earthy particles united in the sea to form the shells of mollusca, the same crystallizing process might be effected on the land, and that, in the latter case, the germs of the animals might have been disseminated through the substance of the rocks, and afterwards developed by virtue of humidity. Visionary as was this doctrine, it gained many proselytes even amongst the more sober reasoners of Italy and Germany, for it conceded both that fossil bodies were organic, and that the diluvial theory could not account for them.

In the mean time, the doctrine that fossil shells had never belonged to real animals, maintained its ground in England, where the agitation of the question began at a much later period. Dr. Plot, in his "Natural History of Oxfordshire," (1677,) attributed to "a plastic virtue latent in the earth" the origin of fossil shells and fishes; and Lister, to his accurate account of British shells, in 1678, added the fossil species, under the appellation of turbinated and bivalve stones. "Either," said he, "these were terriginous, or, if otherwise, the animals they so exactly represent have become extinct." This writer appears to have been the first who was aware of the continuity over large districts of the principal groups of strata in the British series, and who proposed the construction of regular geological maps.

The "Posthumous Works of Robert Hooke, M.D.," well known as a great mathematician and natural philosopher, appeared in 1705, containing, "A Discourse of Earthquakes," which, we are informed by his editor, was written in 1668, but revised at subsequent periods. [19] Hooke frequently refers to the best Italian and English authors who wrote before his time on geological subjects; but there are no passages in his works implying that he participated in the enlarged views of Steno and Lister, or of his contemporary Woodward, in regard to the geographical extent of certain groups of strata. His treatise, however, is the most philosophical production of that age, in regard to the causes of former changes in the organic and inorganic kingdoms of nature.

"However trivial a thing," he says, "a rotten shell may appear to some, yet these monuments of nature are more certain tokens of antiquity than coins or medals, since the best of those may be counterfeited or made by art and design, as may also books, manuscripts, and inscriptions, as all the learned are now sufficiently satisfied has often been actually practised," &c.; "and though it must be granted that it is very difficult to read them (the records of nature) and to raise a chronology out of them, and to state the intervals of the time wherein such or such catastrophes and mutations have happened, yet it is not impossible," &c. [20] Respecting the extinction of species, Hooke was aware that the fossil ammonites, nautili, and many other shells and fossil skeletons found in England, were of different species from any then known; but he doubted whether the species had become extinct, observing that the knowledge of naturalists of all the marine species, especially those inhabiting the deep sea, was very deficient. In some parts of his writings, however, he leans to the opinion that species had been lost; and, in speculating on this subject, he even suggests that there might be some connection between the disappearance of certain kinds of animals and plants, and the changes wrought by earthquakes in former ages: for some species, he observes with great sagacity, are "peculiar to certain places, and not to be found elsewhere. If, then, such a place had been swallowed up, it is not improbable but that those animate beings may have been destroyed with it; and this may be true both of aerial and aquatic animals: for those animated bodies, whether vegetables or animals, which were naturally nourished or refreshed by the air, would be destroyed by the water," &c. [21] Turtles, he adds, and such large ammonites as are found in Portland, seem to have been the productions of the seas of hotter countries, and it is necessary to suppose that England once lay under the sea within the torrid zone! To explain this and similar phenomena, he indulges in a variety of speculations concerning changes in the position of the axis of the earth's rotation, a shifting of the earth's centre of gravity, "analogous to the revolutions of the magnetic pole," &c. None of these conjectures, however, are proposed dogmatically, but rather in the hope of promoting fresh inquiries and experiments.

In opposition to the prejudices of his age, we find him arguing that nature had not formed fossil bodies, "for no other end than to play the mimic in the mineral kingdom" -- that figured stones were "really the several bodies they represent, or the mouldings of them petrified," and "not, as some have imagined, a 'lusus naturae,' sporting herself in the needless formation of useless beings." [22]

It was objected to Hooke, that his doctrine of the extinction of species derogated from the wisdom and power of the Omnipotent Creator; but he answered, that, as individuals die, there may be some termination to the duration of a species; and his opinions, he declared, were not repugnant to Holy Writ: for the Scriptures taught that our system was degenerating, and tending to its final dissolution; "and as, when that shall happen, all the species will be lost, why not some at one time and some at another?" [23]

But his principal object was to account for the manner in which shells had been conveyed into the higher parts of "the Alps, Apennines, and Pyrenean hills, and the interior of continents in general." These and other appearances, he said, might have been brought about by earthquakes," which have turned plains into mountains, and mountains into plains, seas into land, and land into seas, made rivers where there were none before, and swallowed up others that formerly were, &c. &c.; and which, since the creation of the world, have wrought many great changes on the superficial parts of the earth, and have been the instruments of placing shells, bones, plants, fishes, and the like, in those places, where, with much astonishment, we find them." [24] This doctrine, it is true, had been laid down in terms almost equally explicit by Strabo, to explain the occurrence of fossil shells in the interior of continents, and to that geographer, and other writers of antiquity, Hooke frequently refers; but the revival and developement of the system was an important step in the progress of modern science.

He enumerated all the examples known to him of subterranean disturbance, from "the sad catastrophe of Sodom and Gomorrah" down to the Chilian earthquake of 1646. The elevating of the bottom of the sea, the sinking and submersion of the land, and most of the inequalities of the earth's surface, might, he said, be accounted for by the agency of these subterranean causes. He mentions that the coast near Naples was raised during the eruption of Monte Nuovo; and that, in 1591, land rose in the island of St. Michael, during an eruption; and although it would be more difficult, he says, to prove, he does not doubt but that there had been as many earthquakes in the parts of the earth under the ocean, as in the parts of the dry land; in confirmation of which he mentions the immeasurable depth of the sea near some volcanoes. To attest the extent of simultaneous subterranean movements, he refers to an earthquake in the West Indies, in 1690, where the space of earth raised, or "struck upwards" by the shock, exceeded the length of the Alps or the Pyrenees.

As Hooke declared the favourite hypothesis of the day ( that marine fossil bodies were to be referred to Noah's flood") to be wholly untenable, he appears to have felt himself called upon to substitute a diluvial theory of his own, and thus he became involved in countless difficulties and contradictions. "During the great catastrophe," he said, "there might have been a changing of that part which was before dry land into sea by sinking, and of that which was sea into dry land by raising, and marine bodies might have been buried in sediment beneath the ocean, in the interval between the creation and the deluge." [25] Then followed a disquisition on the separation of the land from the waters, mentioned in Genesis: during which operation some places of the shell of the earth were forced outwards, and others pressed downwards or inwards, &c. His diluvial hypothesis very much resembled that of Steno, and was entirely opposed to the fundamental principles professed by him, that he would explain the former changes of the earth in a more natural manner than others had done. When, in despite of this declaration, he required a former "crisis of nature," and taught that earthquakes had become debilitated, and that the Alp, Andes, and other chains, had been lifted up in a few months, his machinery was as extravagant and visionary as that of his most fanciful predecessors; and for this reason, perhaps, his whole theory of earthquakes met with very undeserved neglect.

One of his contemporaries, the celebrated naturalist, Ray, participated in the same desire to explain geological phenomena, by reference to causes less hypothetical than those usually resorted to. [26] In his Essay on "Chaos and Creation" he proposed a system, agreeing in its outline, and in many of its details, with that of Hooke; but his knowledge of natural history enabled him to elucidate the subject with various original observations. Earthquakes, he suggested, might have been the second causes employed at the creation, in separating the land from the waters, and in gathering the waters together into one place. He mentions, like Hooke, the earthquake of 1646, which had violently shaken the Andes for some hundreds of leagues, and made many alterations therein. In assigning a cause for the general deluge, he preferred a change in the earth's centre of gravity to the introduction of earthquakes. Some unknown cause, he said, might have forced the subterranean waters outwards, as was, perhaps, indicated by "the breaking up of the fountains of the great deep."

Ray was one of the first of our writers who enlarged upon the effects of running water upon the land, and of the encroachment of the sea upon the shores. So important did he consider the agency of these causes, that he saw in them an indication of the tendency of our system to its final dissolution; and he wondered why the earth did not proceed more rapidly towards a general submersion beneath the sea, when so much matter was carried down by rivers, or undermined in the seacliffs. We perceive clearly from his writings, that the gradual decline of our system, and its future consummation by fire, was held to be as necessary an article of faith by the orthodox, as was the recent origin of our planet. His Discourses, like those of Hooke, are highly interesting, as attesting the familiar association in the minds of philosophers, in the age of Newton, of questions in physics and divinity. Ray gave an unequivocal proof of the sincerity of his mind, by sacrificing his preferment in the church, rather than take an oath against the Covenanters, which he could not reconcile with his conscience. His reputation, moreover, in the scientific world placed him high above the temptation of courting popularity, by pandering to the physico-theological taste of his age. It is, therefore, curious to meet with so many citations from the Christian fathers and prophets in his essays on physical science -- to find him in one page proceeding by the strict rules of induction, to explain the former changes of the globe, and in the next gravely entertaining the question, whether the sun and stars, and the whole heavens shall be annihilated, together with the earth, at the era of the grand conflagration.

Among the contemporaries of Hooke and Ray, Woodward, a professor of medicine, had acquired the most extensive information respecting the geological structure of the crust of the earth. He had examined many parts of the British strata with minute attention; and his systematic collection of specimens, bequeathed to the University of Cambridge, and still preserved there as arranged by him, shews how far he had advanced in ascertaining the order of superposition. From the great number of facts collected by him we might have expected his theoretical views to be more sound and enlarged than those of his contemporaries; but in his anxiety to accommodate all observed phenomena to the scriptural account of the Creation and Deluge, he arrived at most erroneous results. He conceived "the whole terrestrial globe to have been taken to pieces and dissolved at the flood, and the strata to have settled down from this promiscuous mass as any earthy sediment from a fluid.'' [27] In corroboration of these views, he insisted upon the fact, that "marine bodies are lodged in the strata according to the order of their gravity, the heavier shells in stone, the lighter in chalk, and so of the rest." [28] Ray immediately exposed the unfounded nature of this assertion, remarking truly, that fossil bodies "are often mingled, heavy with light, in the same stratum;" and he even went so far as to say, that Woodward "must have invented the phenomena for the sake of confirming his bold and strange hypothesis" [29] -- a strong expression from the pen of a contemporary.

At the same time Burnet published his "Theory of the Earth." [30] The title is most characteristic of the age, -- "The Sacred Theory of the Earth, containing an Account of the Original of the Earth, and of all the general Changes which it hath already undergone, or is to undergo, till the Consummation of all Things." Even Milton had scarcely ventured in his poem to indulge his imagination so freely in painting scenes of the Creation and Deluge, Paradise and Chaos, as this writer, who set forth pretensions to profound philosophy. He explained why the primeval earth enjoyed a perpetual spring before the flood! shewed how the crust of the globe was fissured by "the sun's rays," so that it burst, and thus the diluvial waters were let loose from a supposed central abyss. Not satisfied with these themes, he derived from the books of the inspired writers, and even from heathen authorities, prophetic views of the future revolutions of the globe, gave a most terrific description of the general conflagration, and proved that a new heaven and a new earth will rise out of a second chaos -- after which will follow the blessed millennium.

The reader should be informed, that according to the opinion of many respectable writers of that age, there was good scriptural ground for presuming that the garden bestowed upon our first parents was not on the earth itself, but above the clouds, in the middle region between our planet and the moon. Burnet approaches with becoming gravity the discussion of so important a topic. He was willing to concede that the geographical position of Paradise was not in Mesopotamia, yet he maintained that it was upon the earth, and in the southern hemisphere, near the equinoctial line. Butler selected this conceit as a fair mark for his satire, when, amongst the numerous accomplishments of Hudibras, he says --

He knew the seat of Paradise,
Could tell in what degree it lies;
And as he was disposed, could prove it
Below the moon, or else above it.


Yet the same monarch, who is said never to have slept without Butler's poem under his pillow, was so great an admirer and patron of Burnet's book, that he ordered it to be translated from the Latin into English. The style of the "Sacred Theory" was eloquent, and displayed powers of invention of no ordinary stamp. It was, in fact, a fine historical romance, as Buffon afterwards declared; but it was treated as a work of profound science in the time of its author, and was panegyrized by Addison in a Latin ode, while Steele praised it in the" Spectator," and Warton, in his "Essay on Pope," discovered that Burnet united the faculty of judgment with powers of imagination.

Another production of the same school, and equally characteristic of the times, was that of Whiston, entitled, "A New Theory of the Earth, wherein the Creation of the World in six Days, the Universal Deluge, and the General Conflagration, as laid down in the Holy Scriptures, are shewn to be perfectly agreeable to Reason and Philosophy." He was at first a follower of Burnet, but his faith in the infallibility of that writer was shaken by the declared opinion of Newton, that there was every presumption in astronomy against any former change in the inclination of the earth's axis. This was a leading dogma in Burnet's system, though not original, for it was borrowed from an Italian, Alessandro degli Alessandri, who had suggested it in the beginning of the fifteenth century, to account for the former occupation of the present continents by the sea. La Place has since strengthened the arguments of Newton, against the probability of any former revolution of this kind. The remarkable comet of 1680 was fresh in the memory of everyone, when Whiston first began his cosmological studies, and the principal novelty of his speculations consisted in attributing the deluge to the near approach to the earth of one of these erratic bodies. Having ascribed an increase of the waters to this source, he adopted Woodward's theory, supposing all stratified deposits to have resulted from the "chaotic sediment of the flood." Whiston was one of the first who ventured to propose that the text of Genesis should be interpreted differently from its ordinary acceptation, so that the doctrine of the earth having existed long previous to the creation of man might no longer be regarded as unorthodox. He had the art to throw an air of plausibility over the most improbable parts of his theory, and seemed to be proceeding in the most sober manner, and by the aid of mathematical demonstration, to the establishment of his various propositions. Locke pronounced a panegyric on his theory, commending him for having explained so many wonderful and before inexplicable things. His book, as well as Burnet's, was attacked and refuted by Keill. [31] Like all who introduced purely hypothetical causes to account for natural phenomena, he retarded the progress of truth, diverting men from the investigation of the laws of sublunary nature, and inducing them to waste time in speculations on the power of comets to drag the waters of the ocean over the land -- on the condensation of the vapours of their tails into water, and other matters equally edifying.

John Hutchinson, who had been employed by Woodward in making his collection of fossils, published afterwards, in 1724, the first part of his "Moses's Principia," wherein he ridiculed Woodward's hypothesis. He and his numerous followers were accustomed to declaim loudly against human learning, and they maintained that the Hebrew scriptures, when rightly translated, comprised a perfect system of natural philosophy, for which reason they objected to the Newtonian theory of gravitation.

Leibnitz, the great mathematician, published his "Protogaea" in 1680. He imagined this planet to have been originally a burning luminous mass, and that ever since its creation it has been undergoing gradual refrigeration. Nearly all the matter of the earth was at first encompassed by fire. When the outer crust had at length cooled down sufficiently to allow the vapours to be condensed, they fell and formed a universal ocean, investing the globe, and covering the loftiest mountains. Further consolidation produced rents, vacuities, and subterranean caverns, and the ocean, rushing in to fill them, was gradually lowered. The principal feature of this theory, the gradual diminution of the original heat, and of an ancient universal ocean, were adopted by Buffon and De Luc, and entered, under different modifications, into a great number of succeeding systems.

Andrea Celsius, the Swedish astronomer, published, about this time, his remarks on the gradual diminution of the waters in the Baltic, which sea, he imagined, had been sinking from time immemorial at the rate of forty-five inches in a century. His opinions gave rise to a controversy which has lasted even to our own days, and to which we are indebted for correct observations of a variety of facts concerning the gradual filling up of the Baltic by fluviatile and marine sediment. Linnaeus [32] favoured the views of Celsius, because they fell in with his own notions concerning a Paradise, where an the animals were created, and from whence they passed into all other parts of the earth, as these became dry in succession.

In Germany, in the meantime, Scheuchzer laboured to prove, in a work entitled the "Complaint of the Fishes," (1708,) that the earth had been remodelled at the deluge. Pluche also, in 1732, wrote to the same effect, while Holbach, in 1753, after considering the various attempts to refer all the ancient formations to the Noachian flood, exposed the insufficiency of the cause.

We return with pleasure to the geologists of Italy, who preceded, as we before saw, the naturalists of other countries in their investigations into the ancient history of the earth, and who still maintained a decided pre-eminence. They refuted and ridiculed the physico-theological systems of Burnet, Whiston, and Woodward, [33] while Vallisneri, [34] in his comments on the Woodwardian theory, remarked how much the interests of religion as well as those of sound philosophy had suffered, by perpetually mixing up the sacred writings with questions in physical science. The works of this author were rich in original observations. He attempted the first general sketch of the marine deposits of Italy, their geographical extent and most characteristic organic remains. In his treatise "On the Origin of Springs," he explained their dependence on the order, and often on the dislocations of the strata, and reasoned philosophically against the opinions of those who regarded the disordered state of the earth's crust as exhibiting signs of the wrath of God for the sins of man. He found himself under the necessity of contending in his preliminary chapter against St. Jerome, and four other principal interpreters of scripture, besides several professors of divinity, "that springs did not flow by subterranean syphons and cavities from the sea upwards, losing their saltness in the passage," for this theory had been made to rest on the infallible testimony of Holy Writ.

Although reluctant to generalize on the rich materials accumulated in his travels, Vallisneri had been so much struck with the remarkable continuity of the more recent marine strata, from one end of Italy to the other, that he came to the conclusion that the ocean formerly extended over the whole earth, and abode there for a long time. This opinion, however untenable, was a great step beyond Woodward's diluvian hypothesis, against which Vallisneri, and after him all the Tuscan geologists, uniformly contended, while it was warmly supported by the members of the Institute of Bologna. [35]

Among others of that day, Spada, a priest of Grezzana, in 1737, wrote to prove that the petrified marine bodies near Verona were not diluvian. [36] Mattani drew similar inference, from the shells of Volterra, and other places; while Costantini, on the other hand, whose observations on the valley of the Brenta and other districts were not without value, undertook to vindicate the truth of the deluge, as also to prove that Italy had been peopled by the descendants of Japhet. [37]
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Re: Principles of Geology, by Charles Lyell

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PART 2 OF 2

Lazzoro Moro, in his work (published in 1740), "On the Marine Bodies which are found in the Mountains," [38] attempted to apply the theory of earthquakes, as expounded by Strabo, Pliny, and other ancient authors, with whom he was familiar, to the geological phenomena described by Vallisneri. [39] His attention was awakened to the elevating power of subterranean forces, by a remarkable phenomenon which happened in his own time, and which had also been noticed by Vallisneri in his letters. A new island rose in 1707, from a deep part of the sea near Santorino in the Mediterranean, during continued shocks of an earthquake, and increasing rapidly in size, grew in less than a month to be half a mile in circumference, and about twenty-five feet above high-water mark. It was soon afterwards covered by volcanic ejections, but when first examined it was found to be a white rock, bearing on its surface living oysters and crustacea. In order to ridicule the various theories then in vogue, Moro ingeniously supposes the arrival on this new isle of a party of naturalists ignorant of its recent origin. One immediately points to the marine shells, as proofs of the universal deluge; another argues, that they demonstrate the former residence of the sea upon the mountains; a third dismisses them as mere sports of nature; while a fourth affirms, that they were born and nourished within the rock in ancient caverns, into which salt water had been raised in the shape of vapour, by the action of subterranean heat.

Moro pointed with great judgment to the faults and dislocations of the strata described by Vallisneri, in the Alps and other chains, in confirmation of his doctrine, that the continents had been heaved up by subterranean movements. He objected, on solid grounds, to the hypotheses of Burnet and of Woodward; yet he ventured so far to disregard the protest of Vallisneri, as to undertake the adaptation of every part of his own system to the Mosaic account of the creation. On the third day, he said the globe was everywhere covered to the same depth by fresh water, and when it pleased the Supreme Being that the dry land should appear, volcanic explosions broke up the smooth and regular surface of the earth composed of primary rocks. These rose in mountain masses above the waves, and allowed melted metals and salts to ascend through fissures. The sea gradually acquired its saltness from volcanic exhalations, and, while it became more circumscribed in area, increased in depth. Sand and ashes ejected by volcanoes were regularly disposed along the bottom of the ocean and formed the secondary strata, which in their turn were lifted up by earthquakes. We shall not attempt to follow him in tracing the progress of the creation of vegetables, and animals on the other days of creation; but, upon the whole, we may remark that few of the old cosmological theories had been conceived with so little violation of known analogies.

The style of Moro was extremely prolix, and, like Hutton, who, at a later period, advanced many of the same views, he stood in need of an illustrator. The Scotch geologist was not more fortunate in the advocacy of Playfair, than was Moro in numbering amongst his admirers Cirillo Generelli, who, nine years afterwards, delivered at a sitting of Academicians at Cremona a spirited exposition of his theory. This learned Carmelitan friar does not pretend to have been an original observer, but he had studied sufficiently to be enabled to confirm the opinions of Moro by arguments from other writers; and his selection of the doctrines then best established is so judicious, that we shall present a brief abstract of them to our readers, as illustrating the state of geology in Europe, and in Italy in particular, before the middle of the last century. The bowels of the earth, says he, have carefully preserved the memorials of past events, and this truth the marine productions so frequent in the hills attest. From the reflections of Lazzaro Moro we may assure ourselves, that these are the effects of earthquakes in past times, which have changed vast spaces of sea into terra firma, and inhabited lands into seas. In this, more than in any other department of physics, are observations and experiments indispensable, and we must diligently consider facts. The land is known, wherever we make excavations, to be composed of different strata or soils placed one above the other, some of sand, some of rock, some of chalk, others of marl, coal, pumice, gypsum, lime, and the rest. These ingredients are sometimes pure, and sometimes confusedly intermixed. Within are often imprisoned different marine fishes, like dried mummies, and more frequently shells, crustacea, corals, plants, &c., not only in Italy, but in France, Germany, England, Africa, Asia, and America. Sometimes in the lowest, sometimes in the loftiest beds of the earth, some upon the mountains; some in deep mines, others near the sea, and others hundreds of miles distant from it. But there are in some districts rocks, wherein no marine bodies are found. The remains of animals consist chiefly of their more solid parts, and the most rocky strata must have been soft when such exuviae were inclosed in them. Vegetable productions are found in different states of maturity, indicating that they were imbedded in different seasons. Elephants, elks, and other terrestrial quadrupeds, have been found in England and elsewhere, in superficial strata, never covered by the sea. Alternations are rare, yet not without example, of marine strata, and those which contain marshy and terrestrial productions. Marine animals are arranged in the subterraneous beds with admirable order, in distinct groups, oysters here, dentalia, or corals there, &c., as now, according to Marsilli, [40] on the shores of the Adriatic. We must abandon the doctrine once so popular, that organized fossils have not been derived from living beings, and we cannot account for their present position by the ancient theory of Strato, nor by that of Leibnitz, nor by the universal deluge, as explained by Woodward and others, "nor is it reasonable to call the Deity capriciously upon the stage, and to make him work miracles, for the sake of confirming our preconceived hypotheses." -- "I hold in utter abomination, most learned Academicians! those systems which are built with their foundations in the air, and cannot be propped up without a miracle; and I undertake, with the assistance of Moro, to explain to you, how these marine animals were transported into the mountains by natural causes." [41] A brief abstract then follows of Moro's theory, by which, says Generelli, we may explain all the phenomena, as Vallisneri so ardently desired, "without violence, without fictions, without hypotheses, without miracles." [42] The Carmelitan then proceeds to struggle against an obvious objection to Moro's system, considered as a method of explaining the revolutions of the earth, naturally. If earthquakes have been the agents of such mighty changes, how does it happen that their effects since the times of history have been so inconsiderable? This same difficulty had, as we have seen, presented itself to Hooke, half a century before, and forced him to resort to a former "crisis of nature;" but Generelli defended his position by shewing how numerous were the accounts of eruptions and earthquakes, of new islands, and of elevations and subsidences of land, and yet how much greater a number of like events must have been unattested and unrecorded during the last six thousand years. He also appealed to Vallisneri as an authority to prove that the mineral masses containing shells bore, upon the whole, but a small proportion to those rocks which were destitute of organic remains; and the latter, says the learned monk, might have been created as they now exist, in the beginning. He then describes the continual waste of mountains and continents, by the action of rivers and torrents, and concludes with these eloquent and original observations: "Is it possible that this waste should have continued for six thousand, and perhaps a greater number of years, and that the mountains should remain so great, unless their ruins have been repaired? Is it credible that the Author of nature should have founded the world upon such laws, as that the dry land should for ever be growing smaller, and at last become wholly submerged beneath the waters? Is it credible that, amid so many created things, the mountains alone should daily diminish in number and bulk, without there being any repair of their losses? This would be contrary to that order of Providence which is seen to reign in all other things in the universe. Wherefore I deem it just to conclude, that the same cause which, in the beginning of time, raised mountains from the abyss, has, down to the present day, continued to produce others, in order to restore from time to time the losses of all such as sink down in different places, or are rent asunder, or in other ways suffer disintegration. If this be admitted, we can easily understand why there should now be found upon many mountains so great a number of crustacea and other marine animals."

The reader will remark, that although this admirable essay embraces so large a portion of the principal objects of geological research, it makes no allusion to the extinction of certain classes of animals; and it is evident that no opinions on this head had, at that time, gained a firm footing in Italy. That Lister and other English naturalists should long before have declared in favour of the loss of species, while Scilla and most of his countrymen hesitated, was natural, since the Italian museums were filled with fossil shells, belonging to species of which a great portion did actually exist in the Mediterranean, whereas the English collectors could obtain no recent species from their own strata.

The weakest point in Moro's system consisted in deriving all the stratified rocks from volcanic ejections, an absurdity which his opponents took care to expose, especially Vito Amici. [43] Moro seems to have been misled by his anxious desire to represent the formation of secondary rocks as having occupied an extremely short period, while at the same time he wished to employ known agents in nature. To imagine torrents, rivers, currents, partial floods, and all the operations of moving water, to have gone on exerting an energy many thousand times greater than at present, would have appeared preposterous and incredible, and would have required a hundred violent hypotheses; but we are so unacquainted with the true sources of subterranean disturbances, that their former violence may in theory be multiplied indefinitely, without its being possible to prove the same manifest contradiction or absurdity in the conjecture. For this reason, perhaps, Moro preferred to derive the materials of the strata from volcanic ejections, rather than from transportation by running water.

Marsilli, in the work above alluded to by Generelli, had been prompted to institute inquiries into the bed of the Adriatic, by discovering in the territory of Parma, (what Spada had observed near Verona, and Schiavo in Sicily,) that fossil shells were not scattered through the rocks at random, but disposed in regular order, according to families. But with a view of throwing further light upon these questions, Donati, in 1750, undertook a more extensive investigation of the Adriatic, and discovered, by numerous soundings, that deposits of sand, marl, and tufaceous incrustations, most strictly analogous to those of the Subapennine hills, were in the act of accumulating there. He ascertained that there were no shells in some of the submarine tracts, while in other places they lived together in families, particularly the genera Area, Pecten, Venus, Murex, and some others. A contemporary naturalist, Baldassari, had shewn the same grouping of organic remains in the tertiary marls of the Sienese territory.

Buffon first made known his theoretical views concerning the former changes of the earth in his Natural History, published in 1749. His opinions were directly opposed to the systems of Hooke, Ray, and Moro, for he attributed no influence whatever to subterranean movements and volcanoes, but returned to the universal ocean of Leibnitz. By this aqueous envelope the highest mountains were once covered. Marine currents then acted violently, and formed horizontal strata, by washing away land in some parts, and depositing it in others; they also excavated deep submarine valleys. He was greatly at a loss for some machinery to depress the level of the ocean, and cause the land to be left dry. He therefore speculated on the possibility of subterranean caverns having opened, into which the water entered, so that he involuntarily approximated to Hooke's theory of subsidences by earthquakes. Buffon had never profited, like Moro, by the observations of Vallisneri, or he never could have imagined that the strata were generally horizontal, and that those which contain organic remains had never been disturbed since the era of their formation. He was conscious of the great power annually exerted by rivers and marine currents in transporting earthy materials to lower levels, and he even contemplated the period when they would destroy all the present continents. Although in geology he was not an original observer, his genius enabled him to render his hypothesis attractive; and by the eloquence of his style, and the boldness of his speculations, he awakened curiosity and provoked a spirit of inquiry amongst his countrymen.

Soon after the publication of his "Natural History," in which was included his "Theory of the Earth," he received an official letter (dated January, 1751), from the Sorbonne or Faculty of Theology in Paris, informing him that fourteen propositions in his works "were reprehensible and contrary to the creed of the church." The first of these obnoxious passages, and the only one relating to geology, was as follows. "The waters of the sea have produced the mountains and valleys of the land -- the waters of the heavens, reducing all to a level, will at last deliver the whole land over to the sea, and the sea, successively prevailing over the land, will leave dry new continents like those which we inhabit." Duffon was invited by the College in very courteous terms, to send in an explanation, or rather a recantation, of his unorthodox opinions. To this he submitted, and a general assembly of the Faculty having approved of his "Declaration," he was required to publish it in his next work. The document begins with these words -- "I declare that I had no intention to contradict the text of Scripture; that I believe most firmly all therein related about the creation, both as to order of time and matter of fact; and I abandon everything in my book respecting the formation of the earth, and generally all which may be contrary to the narration of Moses." [44]

The grand principle which Buffon was called upon to renounce was simply this, "that the present mountains and valleys of the earth are due to secondary causes, and that the same causes will in time destroy all the continents, hills and valleys, and reproduce others like them." Now, whatever may be the defects of many of his views, it is no longer controverted, that the present continents are of secondary origin. The doctrine is as firmly established as the earth's rotation on its axis; and that the land now elevated above the level of the sea will not endure for ever, is an opinion which gains ground daily, in proportion as we enlarge our experience of the changes now in progress.

Hollmann was the author of a Memoir in the Transactions of the Royal Society of Gottingen in 1753, wherein he proposed an hypothesis closely corresponding to the opinions of Buffon; and devoted the rest of his work to refuting certain diluvial theories of his day.

Targioni, in his voluminous" Travels in Tuscany, 1751 and 1754," laboured to fill up the sketch of the geology of that region, left by Steno sixty years before. Notwithstanding a want of arrangement and condensation in his memoirs, they contained a rich store of faithful observations. He has not indulged in many general views, but in regard to the origin of valleys he was opposed to the theory of Buffon, who attributed them principally to submarine currents. The Tuscan naturalist laboured to shew that both the larger and smaller valleys of the Apennines were excavated by rivers, and floods, caused by the bursting of the barriers of lakes, after the retreat of the ocean. He also maintained that the elephants, and other quadrupeds so frequent in the lacustrine and alluvial deposits of Italy, had inhabited that peninsula; and had not been transported thither, as some had conceived, by Hannibal, or the Romans, nor by what they were pleased to term "a catastrophe of nature."

Arduino, [45] in his memoirs on the mountains of Padua, Vicenza, and Verona, first recognized the distinction between primary, secondary, and tertiary rocks, and shewed that in those districts there had been a succession of submarine volcanic eruptions. In the very same year the treatise of Lehman, [46] a German mineralogist, and director of the Prussian mines, appeared, who also divided mountains into three classes: the first, which were formed with the world and prior to the creation of animals, and which contained no fragments of other rocks; the second class, of mountains which resulted from the partial destruction of the primary rocks by a general revolution; and the third class, which resulted from local revolutions, and, in part, from the Noachian deluge.

In the following year (1760) the Rev. John Michell, Woodwardian Professor of Mineralogy at Cambridge, published in the Philosophical Transactions, an Essay on the Cause and Phenomena of Earthquakes. His attention had been drawn to this subject by the great earthquake of Lisbon in 1755. He advanced many original and philosophical views respecting the propagation of subterranean movements, and the caverns and fissures wherein steam might be generated. In order to point out the application of his theory to the structure of the globe, he was led to describe the arrangement and disturbance of the strata, their usual horizontality in low countries, and their contortions and fractured state in the neighbourhood of mountain chains. He also explained, with surprising accuracy, the relations of the central ridges of older rocks to the "long narrow slips of similar earths, stones, and minerals," which are parallel to these ridges. In his generalizations, derived in great part from his own observations on the geological structure of Yorkshire, he anticipated many of the views more fully developed by later naturalists. [47]

Michell's papers were entirely free from all physico-theological disquisitions, but some of his contemporaries were still earnestly engaged in defending or impugning the Woodwardian hypothesis. We find many of these writings referred to by Catcott, an Hutchinsonian, who published a "Treatise on the Deluge" in 1761. He laboured particularly to refute an explanation offered by his contemporary, Bishop Clayton, of the Mosaic writings. That prelate had declared that the Deluge "could not be literally true, save in respect to that part where Noah lived before the flood." Catcott insisted on the universality of the deluge, and referred to traditions of inundations mentioned by ancient writers, or by travellers in the East Indies, China, South America, and other countries. This part of his book is valuable, although it is not easy to see what bearing the traditions have, if admitted to be authentic, on the Bishop's argument, since no evidence is adduced to prove that the catastrophes were contemporaneous events, while some of them are expressly represented by ancient authors to have occurred in succession.

The doctrines of Arduino, above adverted to, were afterwards confirmed by Fortis and Desmarest, in their travels in the same country, and they, as well as Baldassari, laboured to complete the history of the Subapennine strata. In the work of Odoardi, [48] there was also a clear argument in favour of the distinct ages of the older Apennine strata, and the Subapennine formations of more recent origin. He pointed out that the strata of these two groups were unconformable, and must have been the deposits of different seas at distant periods of time.

A history of the new islands by Raspe, an Hanoverian, appeared in 1763, in Latin. In this work, all the authentic accounts of earthquakes which had produced permanent changes on the solid parts of the earth were collected together and examined with judicious criticism. The best systems which had been proposed concerning the ancient history of the globe, both by ancient and modern writers, are reviewed. The merits and defects of the systems of Hooke, Ray, Moro, Buffon, and others, are fairly estimated. Great admiration is expressed for the hypothesis of Hooke, and his explanation of the origin of the strata is shewn to have been more correct than Moro's, while their theory of the effects of earthquakes was the same. Raspe had not seen Michell's memoir, and his views concerning the geological structure of the earth were perhaps less enlarged, yet he was able to add many additional arguments in favour of Hooke's theory, and to render it, as he said, a nearer approach to what Hooke would have written had he lived in later times. As to the periods wherein all the earthquakes happened, to which we owe the elevation of various parts of our continents and islands, Raspe says he pretends not to assign their duration, still less to defend Hooke's suggestion, that the convulsions almost all took place during the Noachian deluge. He adverts to the apparent indications of the former tropical heat of the climate of Europe, and the changes in the species of animals and plants, as among the most obscure and difficult problems in geology. In regard to the islands raised from the sea, within the times of history or tradition, he declares that some of them were composed of strata containing organic remains, and that they were not, as Buffon had asserted, made of mere volcanic matter. His work concludes with an eloquent exhortation to naturalists, to examine the isles which rose in 1707, in the Grecian Archipelago, and in 1720 in the Azores, and not to neglect such splendid opportunities of studying nature "in the act of parturition." That Hooke's writings should have been neglected for more than half a century, was matter of astonishment to Raspe; but, it is still more wonderful that his own luminous exposition of that theory should, for more than another half century, have excited so little interest.

Gustavus Brander published, in 1766, his "Fossilia Hantoniensia," containing excellent figures of fossil shells from the more modern marine strata of our island. "Various opinions," he says in the preface, "had been entertained concerning the time when and how these bodies became deposited. Some there are who conceive that it might have been effected in a wonderful length of time by a gradual changing and shifting of the sea, &c. But the most common cause assigned is that of "the deluge." This conjecture, he says, even if the universality of the flood be not called in question, is purely hypothetical. In his opinion fossil animals and testacea were, for the most part, of unknown species, and of such as were known, the living analogues now belonged to southern latitudes.

Soldani [49] applied successfully his knowledge of zoology to illustrate the history of stratified masses. He explained that microscopic testacea and zoophytes inhabited the depths of the Mediterranean, and that the fossil species were, in like manner, found in those deposits wherein the fineness of their particles, and the absence of pebbles, implied that they were accumulated in a deep sea far from any shore. This author first remarked the alternation of marine and fresh-water strata in the Paris basin. A lively controversy arose between Fortis and another Italian naturalist, Testa, concerning the fish of Monte Bolca, in 1793. Their letters, [50] written with great spirit and elegance, shew that they were aware that a large proportion of the Subapennine shells were identical with living species, and some of them with species now living in the torrid zone. Fortis conjectured that when the volcanos of the Vicentin were burning, the waters of the Adriatic had a higher temperature; and in this manner, he said that the shells of warmer regions may once have peopled their own seas. But Testa was disposed to think, that these species of testacea were still common to their own and to equinoctial seas, for many, he said, once supposed to be confined to hotter regions, had been afterwards discovered in the Mediterranean. [51]

While these Italian naturalists, together with Cortesi and Spallanzani, were busily engaged in pointing out the analogy between the deposits of modern and ancient seas, and the habits and arrangement of their organic inhabitants, and while some progress was making in the same country, in investigating the ancient and modern volcanic rocks, the most original observers among the English and German writers, Wallerius and Whitehurst, [52] were wasting their strength in contending, according to the old Woodwardian hypothesis, that all the strata were formed by the Noachian deluge. But Whitehurst's description of the rocks of Derbyshire was most faithful, and he atoned for false theoretical views, by providing data for their refutation.

The mathematician, Boscovich, of Ragusa in Dalmatia, in his letters, published at Venice in 1772, declared his persuasion, that the effects of earthquakes, although insensible in the course of a few years, do nevertheless raise, from time to time, and let down different parts of the crust of our globe, and sometimes fold and twist them. Like Hooke, Ray, and Moro, he conceived the subterranean movements to have acted with greater energy at former epochs.

Towards the close of the eighteenth century, the idea of distinguishing the mineral masses on our globe into separate groups, and studying their relations, began to be generally diffused. Pallas and Saussure were among the most celebrated whose labours contributed to this end. After an attentive examination of the two great mountain chains of Siberia, Pallas announced the result that the granitic rocks were in the middle, the schistose at their sides, and the limestones again on the outside of these; and this he conceived would prove a general law in the formation of all chains composed chiefly of primary rocks. [53]

In his "Travels in Russia," in 1793 and 1794, he made many geological observations on the recent strata near the Wolga and the Caspian, and adduced proofs of the greater extent of the latter sea at no distant era in the earth's history. His memoir on the fossil bones of Siberia attracted attention to some of the most remarkable phenomena in geology. He stated that he had found a rhinoceros entire in the frozen soil, with its skin and flesh: an elephant, found afterwards in a mass of ice on the shore of the north sea, removed all doubt as to the accuracy of so wonderful a discovery. [54]

The subjects relating to natural history which engaged the attention of Pallas were too multifarious to admit of his devoting a large share of his labours exclusively to geology. Saussure, on the other hand, employed the chief portion of his time in studying the structure of the Alps and Jura, and he provided valuable data for those who followed him. We cannot enter into the details of these observations, and he did not pretend to have arrived at any general system. The few theoretical observations which escaped from him are, like those of Pallas, mere modifications of the old cosmological doctrines.

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Notes:

1. Mod. Univ. Hist. vol. ii. chap. iv. section iii.

2. Von Hoff, Geschichte der Veranderungen der Erdoberflache, vol. i. p. 406, who cites Delisle, bey Hissmann Welt-und Volkergeschichte. Alte Gesch. 1ter Theil. s. 234. -- The Arabian persecutions for heretical dogmas in theology were often very sanguinary. In the same ages wherein learning was most in esteem, the Mahometans were divided into two sects, one of whom maintained that the Koran was increate, and had subsisted in the very essence of God from all eternity; and the other the Motazalites, who, admitting that the Koran was instituted by God, conceived it to have been first made when revealed to the Prophet at Mecca, and accused their opponents of believing in two eternal beings. The opinions of each of these sects were taken up by different caliphs in succession, and the followers of each sometimes submitted to be beheaded, or flogged till at the point of death, rather than renounce their creed. -- Mod. Univ. Hist. vol. ii. chap. 4.

3. Koran, chap. 41.

4. Sale's Koran, chap. 11, see note.

5. Ibid.

6. Kossa, appointed master to the Caliph Al Mamud, was author of a book, entitled, "The History of the Patriarchs and Prophets, from the Creation of the World." -- Mod. Univ. Hist. vol. ii. chap. 4.

7. See Brocchi's Discourse on the Progress of the Study of Fossil Conchology in Italy, where some of the following notices on Italian writers will be found more at large.

8. Museum Calceol.

9. In the monasteries of Sicily in particular, the title-deeds of many valuable grants of land are headed by such preambles, composed by the testators about the period when the good King Roger was expelling the Saracens from that island.

10. De Fossilib. p. 109 and 176.

11. Brocchi, Con. Foss. Subap. Disc. sui Prog. vol. i. p. 5.

12. De Metallicis.

13. Dies Caniculares.

14. Storia Naturale.

15. Osserv. sugli Animali aquat. e terrest. 1626.

16. Scilla quotes the remark of Cicero on the story that a stone in Chios had been cleft open, and presented the head of Paniscus in relief -- "I believe," said the orator, "that the figure bore some resemblance to Paniscus, but not such that you would have deemed it sculptured by Scopas, for chance never perfectly imitates the truth."

17. De Testaceis fossilibus Mus. Septaliani.

18. The opinions of Boyle, alluded to by Quirini, were published a few years before, in a short article entitled "On the bottom of the Sea." From observations collected from the divers of the pearl fishery, Boyle had ascertained that when the waves were six or seven feet high above the surface of the water, there were no signs of agitation at the depth of fifteen fathoms; and that even during heavy gales of wind, the motion of the water was exceedingly diminished at the depth of twelve or fifteen feet. He had also learnt from some of his informants, that there were currents running in opposite directions at different depths. -- Boyle's Works, vol. iii. p. 110. London, 1744. The reader will see, in our chapter on "Marine Currents," that Boyle's doctrine must be received with some modification.

19. Between the year 1688 and his death, in 1703, he read several memoirs to the Royal Society, and delivered lectures on various subjects, relating to fossil remains and the effects of earthquakes.

20. Post. Works, Lecture Feb. 29, 1688.

21. Posth. Works, p. 327.

22. Posth. Works, Lecture Feb. 15,1688. Hooke explained, with considerable clearness, the different modes wherein organic substances may become lapidified; and, among other illustrations, he mentions some silicified palm-wood brought from Africa, on which M. de la Hire had read a memoir to the Royal Academy of France, (June, 1692,) wherein he had pointed out not only the tubes running the length of the trunk, but the roots at one extremity. De la Hire, says Hooke, also treated of certain trees found petrified in "the river that passes by Bakan, in the kingdom of Ava, and which has for the space of ten leagues the virtue of petrifying wood." It is an interesting fact, that the silicified wood of the Irawadi should have attracted attention more than one hundred years ago. Remarkable discoveries have been recently made there of fossil animals and vegetables by Mr. Crawfurd and Dr. Wallich. -- See Geol. Trans. vol. ii. part 3, p. 377, Second Series. De la Hire cites Father Duchatz, in the second volume of "Observations made in the Indies by the Jesuits."

23. Posth. Works, Lecture May 29, 1689.

24. Posth. Works, p. 312.

25. Posth. Works, p. 410.

26. Ray's Physico-theological Discourses were of somewhat later date than Hooke's great work on earthquakes. He speaks of Hooke as one "whom for his learning and deep insight into the mysteries of nature he deservedly honoured.' -- On the Deluge, chap. 4.

27. Essay towards a Natural History of the Earth, 1695. Preface.

28. Ibid. Preface.

29. Consequences of the Deluge, p. 165.

30. First published in Latin, between the years 1680 and 1690.

31. An Examination of Dr. Burnet's Theory, &c. 2d edition, 1734.

32. De Telluris habitabilis Incremento, 1743.

33. Ramazzini even asserted, that the ideas of Burnet were mainly borrowed from a dialogue of one Patrizio; but Brocchi, after reading that dialogue, assures us, that there was scarcely any other correspondence between these systems, except that both were equally whimsical.

34. Dei Corpi marini, Lettere critiche, &c. 1721.

35. Brocchi, p. 28.

36. Ibid. p. 33.

37. Ibid. p. 37.

38. Sui Crostacei ed altri Corpi marini che si trovano sui Monti.

39. Moro does not cite the works of Hooke and Ray, and although so many of his views were in accordance with theirs, he was probably ignorant of their writings, for they had not been translated. As he always refers to the Latin edition of Burnet, and a French translation of Woodward, we may presume that he did not read English.

40. Saggio fisico intorno alla Storia del Mare, part i. p. 24.

41. Abbomino al sommo qualsivoglia sistema, che sia di pianta fabbricato in aria; massime quando e tale, che non passa sostenersi senza un miracolo, &c. De' Crostacei e di altre produz. del Mare, &c.1749.

42. Senza violenze, senza finzioni, senza supposti, senza miracoli. -- Ib.

43. Sui Testacei della Sicilia.

44. Hist. Nat. tom. v. Ed. de l'Imp. Royale, Paris, 1769.

45. Giornale del Griselini, 1759.

46. Essai d'une Hist. Nat. de Couches de la Terre, 1759.

47. Some of Michell's observations anticipate in so remarkable a manner the theories established forty years afterwards, that his writings would probably have formed an era in the science, if his researches had been uninterrupted. He held, however, his professorship only eight years, when he succeeded to a benefice, and from that time he appears to have entirely discontinued his scientific pursuits.

48. Sui Corpi Marini del Feltrino, 1761.

49. Saggio orittografico, &c. 1780, and other Works.

50. Lett. sui Pesci Fossili di Bolca. Milan, 1793.

51. This argument of Testa has been strengthened of late years by the discovery, that dealers in shells had long been in the habit of selling Mediterranean species as shells of more southern and distant latitudes, for the sake of enhancing their price. It appears, moreover, from several hundred experiments made by that distinguished hydrographer Captain Smyth, on the water within eight fathoms of the surface, that the temperature of the Mediterranean is on an average 34° of Fahrenheit higher than the western part of the Atlantic ocean; an important fact which in some degree may help to explain why many species are common to tropical latitudes, and to the Mediterranean.

52. Inquiry into the Original State and Formation of the Earth. 1778.

53. Observe on the Formation of Mountains, Act. Petrop. ann. 1778, part i.

54. Nov. comm. Petro XVII. Cuvier, Eloge de Pallas.
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Re: Principles of Geology, by Charles Lyell

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CHAPTER 4

Werner's application of Geology to the art of Mining -- Excursive character of his Lectures -- Enthusiasm of his pupils -- His authority -- His theoretical errors -- Desmarest's Map and Description of Auvergne -- Controversy between the Vulcanists and Neptunists -- Intemperance of the rival Sects -- Hutton's Theory of the Earth -- His discovery of Granite Veins -- Originality of his Views -- Why opposed -- Playfair's Illustrations -- Influence of Voltaire's Writings on Geology -- Imputations cast on the Huttonians by Williams, Kirwan, and De Luc -- Smith's Map of England -- Geological Society of London -- Progress of the Science in France -- Growing Importance of the Study of Organic Remains.

THE art of mining has long been taught in France, Germany, and Hungary, in scientific institutions established for that purpose, where mineralogy has always been a principal branch of instruction. [1]

Werner was named, in 1775, professor of that science in the "School of Mines" at Freyberg in Saxony. He directed his attention not merely to the composition and external characters of minerals, but also to what he termed "geognosy," or the natural position of minerals in particular rocks, together with the grouping of those rocks, their geographical distribution, and various relations. The phenomena observed in the structure of the globe had hitherto served for little else than to furnish interesting topics for philosophical discussion; but when Werner pointed out their application to the practical purposes of mining, they were instantly regarded by a large class of men as an essential part of their professional education, and from that time the science was cultivated in Europe more ardently and systematically. Werner's mind was at once imaginative and richly stored with miscellaneous knowledge. He associated everything with his favourite science, and in his excursive lectures he pointed out all the economical uses of minerals, and their application to medicine; the influence of the mineral composition of rocks upon the soil, and of the soil upon the resources, wealth, and civilization of man. The vast sandy plains of Tartary and Africa he would say retained their inhabitants in the shape of wandering shepherds; the granitic mountains and the low calcareous and alluvial plains gave rise to different manners, degrees of wealth and intelligence. The history even of languages, and the migrations of tribes had, according to him, been determined by the direction of particular strata. The qualities of certain stones used in building would lead him to descant on the architecture of different ages and nations, and the physical geography of a country frequently invited him to treat of military tactics. The charm of his manners and his eloquence kindled enthusiasm in the minds of all his pupils, many of whom only intended at first to acquire a slight knowledge of mineralogy; but, when they had once heard him, they devoted themselves to it as the business of their lives. In a few years a small school of mines, before unheard of in Europe, was raised to the rank of a great university, and men already distinguished in science studied the German language, and came from the most distant countries to hear the great oracle of geology. [2]

Werner had a great antipathy to the mechanical labour of writing, and he could never be persuaded to pen more than a few brief memoirs, and those containing no development of his general views. Although the natural modesty of his disposition was excessive, approaching even to timidity, he indulged in the most bold and sweeping generalizations, and he inspired all his scholars with a most implicit faith in his doctrines. Their admiration of his genius, and the feelings of gratitude and friendship which they all felt for him, were not undeserved; but the supreme authority usurped by him over the opinions of his contemporaries, was eventually prejudicial to the progress of the science, so much so, as greatly to counterbalance the advantages which it derived from his exertions. If it be true that delivery be the first, second, and third requisite in a popular orator, it is no less certain that to travel is of threefold importance to those who desire to originate just and comprehensive views concerning the structure of our globe, and Werner had never travelled to distant countries. He had merely explored a small portion of Germany, and conceived, and persuaded others to believe, that the whole surface of our planet, and all the mountain chains in the world, were made after the model of his own province. It was a ruling object of ambition in the minds of his pupils to confirm the generalizations of their great master, and to discover in the most distant parts of the globe his "universal formations," which he supposed had been each in succession simultaneously precipitated over the whole earth from a common menstruum, or "chaotic fluid." Unfortunately, the limited district examined by the Saxon professor was no type of the world, nor even of Europe; and, what was still more deplorable, when the ingenuity of his scholars had tortured the phenomena of distant countries, and even of another hemisphere, into conformity with his theoretical standard, it was discovered that "the master" had misinterpreted many of the appearances in the immediate neighbourhood of Freyberg.

Thus, for example, within a day's journey of his school, the porphyry, called by him primitive, has been found not only to send forth veins or dikes through strata of the coal formation, but to overlie them in mass. The granite of the Hartz mountains, on the other hand, which he supposed to be the nucleus of the chain, is now well known to traverse and breach the other beds, penetrating even into the plain (as near Goslar); and nearer Freyberg, in the Erzgebirge, the mica slate does not mantle round the granite, as the professor supposed, but abuts abruptly against it. But it is still more remarkable, that in the Hartz mountains all his flotz rocks, which he represented as horizontal, are highly inclined, and often nearly vertical, as the chalk at Goslar, and the green sand near Blankenberg.

The principal merit of Werner's system of instruction consisted in steadily directing the attention of his scholars to the constant relations of certain mineral groups, and their regular order of superposition. But he had been anticipated, as we have shewn in the last chapter, in the discovery of this general law, by several geologists in Italy and elsewhere; and his leading divisions of the secondary strata were at the same time made the basis of an arrangement of the British strata by our countryman, William Smith, to whose work we shall return by-and-by. In regard to basalt and other igneous rocks, Werner's theory was original, but it was also extremely erroneous. The basalts of Saxony and Hesse, to which his observations were chiefly confined, consisted of tabular masses capping the hills, and not connected with the levels of existing valleys, like many in Auvergne and the Vivarais. These basalts, and all other rocks of the same family in other countries, were, according to him, chemical precipitates from water. He denied that they were the products of submarine volcanos, and even taught that, in the primeval ages of the world, there were no volcanos. His theory was opposed, in a two-fold sense, to the doctrine of uniformity in the course of nature; for not only did he introduce, without scruple, many imaginary causes supposed to have once effected great revolutions in the earth, and then to have become extinct, but new ones also were feigned to have come into play in modern times; and, above all, that most violent instrument of change, the agency of subterranean fire. So early as 1768, before Werner had commenced his mineralogical studies, Raspe had truly characterized the basalts of Hesse as of igneous origin. Arduino, as we have already seen, had pointed out numerous varieties of trap-rock in the Vicentin, as analogous to volcanic products, and as distinctly referrible to ancient submarine eruptions. Desmarest, as we stated, had, in company with Fortis, examined the Vicentin in 1766, and confirmed Arduino's views. In 1772, Banks, Solander, and Troil, compared the columnar basalt of Hecla with that of the Hebrides. Collini, in 1774, recognised the true nature of the igneous rocks on the Rhine, between Andernach and Bonn. In 1775, Guettard visited the Vivarais, and established the relation of basaltic currents to lavas. Lastly, in 1779, Faujas published his description of the volcanos of the Vivarais and Velay, and shewed how the streams of basalt had poured out from craters which still remain in a perfect state. [3]

When sound opinions had for twenty years prevailed in Europe concerning the true nature of the ancient trap-rocks, Werner by his dictum caused a retrograde movement, and not only overturned the true theory, but substituted for it one of the most unphilosophical ever advanced in any science. The continued ascendancy of his dogmas on this subject was the more astonishing, because a variety of new and striking facts were daily accumulated in favour of the correct opinions first established. Desmarest, after a careful examination of Auvergne, pointed out first the most recent volcanos which had their craters still entire, and their streams of lava conforming to the level of the present river-courses. He then shewed that there were others of an intermediate epoch, whose craters were nearly effaced, and whose lavas were less intimately connected with the present valleys; and, lastly, that there were volcanic rocks still more ancient, without any discernible craters or scoriae, and bearing the closest analogy to rocks in other parts of Europe, the igneous origin of which was denied by the school of Freyberg. [4]

Desmarest's map of Auvergne was a work of uncommon merit. He first made a trigonometrical survey of the district, and delineated its physical geography with minute accuracy and admirable graphic power. He contrived, at the same time, to express, without the aid of colours, a vast quantity of geological detail, the different ages, and sometimes even the structure of the volcanic rocks, distinguishing them from the fresh-water and the granitic. They alone who have carefully studied Auvergne, and traced the different lava streams from their craters to their termination, -- the various isolated basaltic cappings, -- the relation of some lavas to the present valleys, the absence of such relations in others, -- can appreciate the extraordinary fidelity of this elaborate work. No other district of equal dimensions in Europe exhibits, perhaps, so beautiful and varied a series of phenomena; and, fortunately, Desmarest possessed at once the mathematical knowledge required for the construction of a map, skill in mineralogy, and a power of original generalization.

Dolomieu, another of Werner's contemporaries, had found prismatic basalts among the ancient lavas of Etna, and in 1784 had observed the alternations of submarine and calcareous strata in the Val di Noto in Sicily. [5] In 1790, he also described similar phenomena in the Vicentin and in the Tyrol. [6] Montlosier also published, in 1788, an elegant and spirited essay on the volcanos of Auvergne, combining accurate local observations with comprehensive views. In opposition to this mass of evidence, the scholars of Werner were prepared to support his opinions to their utmost extent, maintaining in the fulness of their faith that even obsidian was an aqueous precipitate. As they were blinded by their veneration for the great teacher, they were impatient of opposition, and soon imbibed the spirit of a faction; and their opponents, the Vulcanists, were not long in becoming contaminated with the same intemperate zeal. Ridicule and irony were weapons more frequently employed than argument by the rival sects, till at last the controversy was carried on with a degree of bitterness, almost unprecedented in questions of physical science. Desmarest alone, who had long before provided ample materials for refuting such a theory, kept aloof from the strife, and whenever a zealous Neptunist wished to draw the old man into an argument, he was satisfied with replying, "Go and see." [7]

It would be contrary to all analogy, in matters of graver import, that a war should rage with such fury on the continent, and that the inhabitants of our island should not mingle in the affray. Although in England the personal influence of Werner was wanting to stimulate men to the defence of the weaker side of the question, they contrived to find good reason for espousing the Wernerian errors with great enthusiasm. In order to explain the peculiar motives which led many to enter, even with party feeling, into this contest, we must present the reader with a sketch of the views unfolded by Hutton, a contemporary of the Saxon geologist. That naturalist had been educated as a physician, but, declining the practice of medicine, he resolved, when young, to remain content with the small independence inherited from his father, and thenceforth to give his undivided attention to scientific pursuits. He resided at Edinburgh, where he enjoyed the society of many men of high attainments, who loved him for the simplicity of his manners and the sincerity of his character. His application was unwearied, and he made frequent tours through different parts of England and Scotland, acquiring considerable skill as a mineralogist, and constantly arriving at grand and comprehensive views in geology. He communicated the results of his observations unreservedly, and with the fearless spirit of one who was conscious that love of truth was the sole stimulus of all his exertions. When at length he had matured his views, he published, in 1788, his "Theory of the Earth," [8] and the same, afterwards more fully developed in a separate work, in 1795. This treatise was the first in which geology was declared to be in no way concerned about "questions as to the origin of things;" the first in which an attempt was made to dispense entirely with all hypothetical causes, and to explain the former changes of the earth's crust, by reference exclusively to natural agents. Hutton laboured to give fixed principles to geology, as Newton had succeeded in doing to astronomy; but in the former science too little progress had been made towards furnishing the necessary data to enable any philosopher, however great his genius, to realize so noble a project.

"The ruins of an older world," said Hutton, "are visible in the present structure of our planet, and the strata which now compose our continents have been once beneath the sea, and were formed out of the waste of pre-existing continents. The same forces are still destroying, by chemical decomposition or mechanical violence, even the hardest rocks, and transporting the materials to the sea, where they are spread out, and form strata analogous to those of more ancient date. Although loosely deposited along the bottom of the ocean, they become afterwards altered and consolidated by volcanic heat, and then heaved up, fractured and contorted." Although Hutton had never explored any region of active volcanos, he had convinced himself that basalt and many other trap-rocks were of igneous origin, and that many of them had been injected in a melted state through fissures in the older strata. The compactness of these rocks, and their different aspect from that of ordinary lava, he attributed to their having tooled down under the pressure of the sea, and in order to remove the objections started against this theory, his friend Sir James Hall instituted a most curious and instructive series of chemical experiments, illustrating the crystalline arrangement and texture assumed by melted matter cooled down under high pressure. The absence of stratification in granite, and its analogy in mineral character to rocks which he deemed of igneous origin, led Hutton to conclude that granite must also have been formed from matter in fusion, and this inference he felt could not be fully confirmed, unless he discovered at the contact of granite and other strata a repetition of the phenomena exhibited so constantly by the trap-rocks. Resolved to try his theory by this test, he went to the Grampians and surveyed the line of junction of the granite and superincumbent stratified masses, and found in Glen Tilt in 1785 the most clear and unequivocal proofs in support of his views. Veins of red granite are there seen branching out from the principal mass, and traversing the black micaceous schist and primary limestone. The intersected stratified rocks are so distinct in colour and appearance as to render the example in that locality most striking, and the alteration of the limestone in contact was very analogous to that produced by trap veins on calcareous strata. This verification of his system filled him with delight, and called forth such marks of joy and exultation, that the guides who accompanied him, says his biographer, were convinced that he must have discovered a vein of silver or gold. [9] He was aware that the same theory would not explain the origin of the primary schists, but these he called primary, rejecting the term primitive, and was disposed to consider them as sedimentary rocks altered by heat, and that they originated in some other form from the waste of previously existing rocks.

By this important discovery of granite veins to which he had been led by fair induction from an independent class of facts, Hutton prepared the way for the greatest innovation on the systems of his predecessors. Vallisneri had pointed out the general fact, that there were certain fundamental rocks which contained no organic remains, and which he supposed to have been formed before the creation of living beings. Moro, Generelli, and other Italian writers embraced the same doctrine, and Lehman regarded the mountains called by him primitive, as parts of the original nucleus of the globe. The same tenet was an article of faith in the school of Freyberg; and if anyone ventured to doubt the possibility of our being enabled to carry back our researches to the creation of the present order of things, the granitic rocks were triumphantly appealed to. On them seemed written in legible characters, the memorable inscription

Dinanzi a me non fur cose create
Se non eterne,
[To rear me was the task of power divine]

and no small sensation was excited when Hutton seemed, with unhallowed hand, desirous to erase characters already regarded by many as sacred. "In the economy of the world," said the Scotch geologist, "I can find no traces of a beginning, no prospect of an end ;" and the declaration was the more startling when coupled with the doctrine, that all past changes on the globe had been brought about by the slow agency of existing causes. The imagination was first fatigued and overpowered by endeavouring to conceive the immensity of time required for the annihilation of whole continents by so insensible a process. Yet when the thoughts had wandered through these interminable periods, no resting place was assigned in the remotest distance. The oldest rocks were represented to be of a derivative nature, the last of an antecedent series, and that perhaps one of many pre-existing worlds. Such views of the immensity of past time, like those unfolded by the Newtonian philosophy in regard to space, were too vast to awaken ideas of sublimity unmixed with a painful sense of our incapacity to conceive a plan of such infinite extent. Worlds are seen beyond worlds immeasurably distant from each other, and beyond them all innumerable other systems are faintly traced on the confines of the visible universe.

The characteristic feature of the Huttonian theory was, as before hinted, the exclusion of all causes not supposed to belong to the present order of nature. Its greatest defect consisted in the undue influence attributed to subterranean heat, which was supposed necessary for the consolidation of all submarine deposits. Hutton made no step beyond Hooke, Moro, and Raspe, in pointing out in what manner the laws now governing earthquakes, might bring about geological changes, if sufficient time be allowed. On the contrary, he seems to have fallen far short of some of their views. He imagined that the continents were first gradually destroyed, and when their ruins had furnished materials for new continents, they were upheaved by violent and paroxysmal convulsions. He therefore required alternate periods of disturbance and repose, and such he believed had been, and would for ever be, the course of nature. Generelli, in his exposition of Moro's system, had made a far nearer approximation towards reconciling geological appearances with the state of nature as known to us, for while he agreed with Hutton, that the decay and reproduction of rocks were always in progress, proceeding with the utmost uniformity, the learned Carmelitan represented the repairs of mountains by elevation from below, to be effected by an equally constant and synchronous operation. Neither of these theories considered singly, satisfies all the conditions of the great problem, which a geologist, who rejects cosmological causes, is called upon to solve; but they probably contain together the germs of a perfect system. There can be no doubt, that periods of disturbance and repose have followed each other in succession in every region of the globe, but it may be equally true, that the energy of the subterranean movements has been always uniform as regards the whole earth. The force of earthquakes may for a cycle of years have been invariably confined, as it is now, to large but determinate spaces, and may then have gradually shifted its position, so that another region, which had for ages been at rest, became in its turn the grand theatre of action.

Although Hutton's knowledge of mineralogy and chemistry was considerable, he possessed but little information concerning organic remains. They merely served him as they did Werner to characterize certain strata, and to prove their marine origin. The theory of former revolutions in organic life was not yet fully recognized, and without this class of proofs in support of the antiquity of the globe, the indefinite periods demanded by the Huttonian hypothesis appeared visionary to many, and some, who deemed the doctrine inconsistent with revealed truths, indulged very uncharitable suspicions of the motives of its author. They accused him of a deliberate design of reviving the heathen dogma of an "eternal succession," and of denying that this world ever had a beginning. Playfair, in the biography of his friend, has the following comment on this part of their theory: -- "In the planetary motions, where geometry has carried the eye so far, both into the future and the past, we discover no mark either of the commencement or termination of the present order. It is unreasonable, indeed, to suppose that such marks should anywhere exist. The Author of nature has not given laws to the universe, which, like the institutions of men, carry in themselves the elements of their own destruction. He has not permitted in His works any symptom of infancy or of old age, or any sign by which we may estimate either their future or their past duration. He may put an end, as he no doubt gave a beginning, to the present system at some determinate period of time; but we may rest assured that this great catastrophe will not be brought about by the laws now existing, and that it is not indicated by any thing which we perceive." [10]

The party feeling excited against the Huttonian doctrines, and the open disregard of candour and temper in the controversy, will hardly be credited by our readers, unless we recall to their recollection that the mind of the English public was at that time in a state of feverish excitement. A class of writers in France had been labouring industriously for many years, to diminish the influence of the clergy, by sapping the foundation of the Christian faith, and their success, and the consequences of the Revolution, had alarmed the most resolute minds, while the imagination of the more timid was continually haunted by dread of innovation, as by the phantom of some fearful dream.

Voltaire had used the modern discoveries in physics as one of the numerous weapons of attack and ridicule directed by him against the Scriptures. He found that the most popular systems of geology were accommodated to the sacred writings, and that much ingenuity had been employed to make every fact coincide exactly with the Mosaic account of the creation and deluge. It was, therefore, with no friendly feelings, that he contemplated the cultivators of geology in general, regarding the science as one which had been successfully enlisted by theologians as an ally in their cause. [11] He knew that the majority of those who were aware of the abundance of fossil shells in the interior of continents, were still persuaded that they were proofs of the universal deluge; and as the readiest way of shaking this article of faith, he endeavoured to inculcate scepticism, as to the real nature of such shells, and to recall from contempt the exploded dogma of the sixteenth century, that they were sports of nature. He also pretended that vegetable impressions were not those of real plants. [12] Yet he was perfectly convinced that the shells had really belonged to living testacea, as may be seen in his essay, "On the formation of Mountains." [13] He would sometimes, in defiance of all consistency, shift his ground when addressing the vulgar; and admitting the true nature of the shells collected in the Alps, and other places, pretend that they were eastern species, which had fallen from the hats of pilgrims coming from Syria. The numerous essays written by him on geological subjects were all calculated to strengthen prejudices, partly because he was ignorant of the real state of the science, and partly from his bad faith. [14] On the other hand, they who knew that his attacks were directed by a desire to invalidate scripture, and who were unacquainted with the true merits of the question, might well deem the old diluvian hypothesis incontrovertible, if Voltaire could adduce no better argument against it, than to deny the true nature of organic remains.

It is only by careful attention to impediments originating in extrinsic causes, that we can explain the slow and reluctant adoption of the simplest truths in geology. First, we find many able naturalists adducing the fossil remains of marine animals, as proofs of an event related in Scripture. The evidence is deemed conclusive by the multitude for a century or more; for it favours opinions which they entertained before, and they are gratified by supposing them confirmed by fresh and unexpected proofs. Many, who see through the fallacy, have no wish to undeceive those who are influenced by it, approving the effect of the delusion, and conniving at it as a pious fraud; until finally, an opposite party, who are hostile to the sacred writings, labour to explode the erroneous opinion, by substituting for it another dogma which they know to be equally unsound.

The heretical vulcanists were now openly assailed in England, by imputations of the most illiberal kind. We cannot estimate the malevolence of such a persecution, by the pain which similar insinuations might now inflict; for although charges of infidelity and atheism must always be odious, they were injurious in the extreme at that moment of political excitement: and it was better perhaps for a man's good reception in society, that his moral character should have been traduced, than that he should become a mark for these poisoned weapons. We shall pass over the works of numerous divines, who may be excused for sensitiveness on points which then excited so much uneasiness in the public mind; and we shall say nothing of the amiable poet Cowper, [15] who could hardly be expected to have inquired into the merits of doctrines in physics. But we find in the foremost ranks of the intolerant, several laymen who had high claims to scientific reputation. Amongst these, appears Williams, a mineral surveyor of Edinburgh, who published a "Natural History of the Mineral Kingdom" in 1789, a work of great merit for that day, and of practical utility, as containing the best account of the coal strata. In his preface he misrepresents Hutton's theory altogether, and charges him with considering all rocks to be lavas of different colours and structure; and also with "warping every thing to support the eternity of the world." [16] He descants on the pernicious influence of such sceptical notions, as leading to downright infidelity and atheism, "and as being nothing less than to depose the Almighty Creator of the universe from his office." [17]

Kirwan, president of the Royal Academy of Dublin, a chemist and mineralogist of some merit, but who possessed much greater authority in the scientific world than he was entitled by his talents to enjoy, in the introduction to his "Geological Essays, 1799," said "that sound geology graduated into religion, and was required to dispel certain systems of atheism or infidelity, of which they had had recent experience." [18] He was an uncompromising defender of the aqueous theory of all rocks, and was scarcely surpassed by Burnet and Whiston, in his desire to adduce the Mosaic writings in confirmation of his opinions.

De Luc, in the preliminary discourse to his Treatise on Geology, [19] says, "the weapons have been changed by which revealed religion is attacked; it is now assailed by geology, and this science has become essential to theologians." He imputes the failure of former geological systems to their having been anti-mosaical, and directed against a "sublime tradition." These and similar imputations, reiterated in the works of De Luc, seem to have been taken for granted by some modern writers: it is therefore necessary to state, in justice to the numerous geologists of different nations, whose works we have considered, that none of them were guilty of endeavouring, by arguments drawn from physics, to invalidate scriptural tenets. On the contrary, the majority of them, who were fortunate enough "to discover the true causes of things," did not deserve another part of the poet's panegyric, "Atque metus omnes subjecit pedibus." The caution, and even timid reserve, of many eminent Italian authors of the earlier period is very apparent; and there can hardly be a doubt that they subscribed to certain dogmas, and particularly to the first diluvian theory, out of deference to popular prejudices, rather than from conviction. If they were guilty of dissimulation, we must not blame their want of moral courage, but reserve our condemnation for the intolerance of the times, and that inquisitorial power which forced Galileo to abjure, and the two Jesuits to disclaim the theory of Newton. [20]

Hutton answered Kirwan's attacks with great warmth, and with the indignation excited by unmerited reproach. He had always displayed, says Playfair, "the utmost disposition to admire the beneficent design manifested in the structure of the world, and he contemplated with delight those parts of his theory which made the greatest additions to our knowledge of final causes." We may say with equal truth, that in no scientific works in our language can more eloquent passages be found, concerning the fitness, harmony, and grandeur of all parts of the creation, than in those of Playfair. They are evidently the unaffected expressions of a mind, which contemplated the study of nature, as best calculated to elevate our conceptions of the attributes of the First Cause. At any other time the force and elegance of Playfair's style must have insured popularity to the Huttonian doctrines; but, by a singular coincidence, neptunianism and orthodoxy were now associated in the same creed; and the tide of prejudice ran so strong, that the majority were carried far away into the chaotic fluid, and other cosmological inventions of Werner. These fictions the Saxon Professor had borrowed with little modification, and without any improvement, from his predecessors. They had not the smallest foundation, either in Scripture, or in common sense, but were perhaps approved of by many as being so ideal and unsubstantial, that they could never come into violent collision with any preconceived opinions.

The great object of De Luc's writings was to disprove the high antiquity attributed by Hutton to our present continents, and particularly to seek out some cause for the excavation of valleys more speedy and violent than the action of ordinary rivers. Hutton had said, that the erosion of rivers, and such floods as occur in the usual course of nature, might progressively, if time be allowed, hollow out great valleys, but he had also observed, "that on our continents there is no spot on which a river may not formerly have run." [21] De Luc generally reasoned against him as if he had said, that the existing rivers flowing at their present levels had caused all these inequalities of the earth's surface; and Playfair, in his zeal to prove how much De Luc underrated the force of running water, did not sufficiently expose his misstatement of the Huttonian proposition. But we must defer the full consideration of this controverted question for the present.

While the tenets of the rival schools of Freyberg and Edinburgh were warmly espoused by devoted partisans, the labours of an individual, unassisted by the advantages of wealth or station in society, were almost unheeded. Mr. William Smith, an English surveyor, published his "Tabular View of the British Strata" in 1790, wherein he proposed a classification of the secondary formations in the west of England. Although he had not communicated with Werner, it appeared by this work that he had arrived at the same views respecting the laws of superposition of stratified rocks; that he was aware that the order of succession of different groups was never inverted; and that they might be identified at very distant points by their peculiar organized fossils.

From the time of the appearance of the "Tabular View," he laboured to construct a geological map of the whole of England, and, with the greatest disinterestedness of mind, communicated the results of his investigations to all who desired information, giving such publicity to his original views, as to enable his contemporaries almost to compete with him in the race. The execution of his map was completed in 1815, and remains a lasting monument of original talent and extraordinary perseverance, for he had explored the whole country on foot without the guidance of previous observers, or the aid of fellow-labourers, and had succeeded in throwing into natural divisions the whole complicated series of British rocks. [22] D'Aubuisson, a distinguished pupil of Werner, paid a just tribute of praise to this remarkable performance, observing that "what many celebrated mineralogists had only accomplished for a small part of Germany in the course of half a century, had been effected by a single individual for the whole of England."

We have now arrived at the era of living authors, and shall bring to a conclusion our sketch of the progress of opinion in geology. The contention of the rival factions of the Vulcanists and Neptunists had been carried to such a height, that these names had become terms of reproach, and the two parties had been less occupied in searching for truth, than for such arguments as might strengthen their own cause, or serve to annoy their antagonists. A new school at last arose who professed the strictest neutrality, and the utmost indifference to the systems of Werner and Hutton, and who were resolved diligently to devote their labours to observation. The reaction, provoked by the intemperance of the conflicting parties, now produced a tendency to extreme caution. Speculative views were discountenanced, and through fear of exposing themselves to the suspicion of a bias towards the dogmas of a party, some geologists became anxious to entertain no opinion whatever on the causes of phenomena, and were inclined to scepticism even where the conclusions deducible from observed facts scarcely admitted of reasonable doubt. But although the reluctance to theorize was carried somewhat to excess, no measure could be more salutary at such a moment than a suspension of all attempts to form what were termed "theories of the earth." A great body of new data were required, and the Geological Society of London, founded in 1807, conduced greatly to the attainment of this desirable end. To multiply and record observations, and patiently to await the result at some future period, was the object proposed by them, and it was their favourite maxim that the time was not yet come for a general system of geology, but that all must be content for many years to be exclusively engaged in furnishing materials for future generalizations. By acting up to these principles with consistency, they in a few years disarmed all prejudice, and rescued the science from the imputation of being a dangerous, or at best but a visionary pursuit.

Inquiries were at the same time prosecuted with great success by the French naturalists, who devoted their attention especially to the study of organic remains. They spewed that the specific characters of fossil shells and vertebrated animals might be determined with the utmost precision, and by their exertions a degree of accuracy was introduced into this department of science, of which it had never before been deemed susceptible. It was found that, by the careful discrimination of the fossil contents of strata, the contemporary origin of different groups could often be established, even where all identity of mineralogical character was wanting, and where no light could be derived from the order of superposition. The minute investigation, moreover, of the relics of the animate creation of former ages, had a powerful effect in dispelling the illusion which had long prevailed concerning the absence of analogy between the ancient and modern state of our planet. A close comparison of the recent and fossil species, and the inferences drawn in regard to their habits, accustomed the geologist to contemplate the earth as having been at successive periods the dwelling place of animals and plants of different races, some of which were discovered to have been terrestrial and others aquatic -- some fitted to live in seas, others in the waters of lakes and rivers. By the consideration of these topics, the mind was slowly and insensibly withdrawn from imaginary pictures of catastrophes and chaotic confusion, such as haunted the imagination of the early cosmogonists. Numerous proofs were discovered of the tranquil deposition of sedimentary matter and the slow development of organic life. If many still continued to maintain, that "the thread of induction was broken," yet in reasoning by the strict rules of induction from recent to fossil species, they virtually disclaimed the dogma which in theory they professed. The adoption of the same generic, and, in some cases, even the same specific names for the exuviae of fossil animals, and their living analogues, was an important step towards familiarizing the mind with the idea of the identity and unity of the system in distant eras. It was an acknowledgment, as it were, that a considerable part of the ancient memorials of nature were written in a living language. The growing importance then of the natural history of organic remains, and its general application to geology, may be pointed out as the characteristic feature of the progress of the science during the present century. This branch of knowledge has already become an instrument of great power in the discovery of truths in geology, and is continuing daily to unfold new data for grand and enlarged views respecting the former changes of the earth.

When we compare the result of observations in the last thirty years with those of the three preceding centuries, we cannot but look forward with the most sanguine expectations to the degree of excellence to which geology may be carried, even by the labours of the present generation. Never, perhaps, did any science, with the exception of astronomy, unfold, in an equally brief period, so many novel and unexpected truths, and overturn so many preconceived opinions. The senses had for ages declared the earth to be at rest, until the astronomer taught that it was carried through space with inconceivable rapidity. In like manner was the surface of this planet regarded as having remained unaltered since its creation, until the geologist proved that it had been the theatre of reiterated change, and was still the subject of slow but never ending fluctuations. The discovery of other systems in the boundless regions of space was the triumph of astronomy -- to trace the same system through various transformations -- to behold it at successive eras adorned with different hills and valleys, lakes and seas, and peopled with new inhabitants, was the delightful meed of geological research. By the geometer were measured the regions of space, and the relative distances of the heavenly bodies -- by the geologist myriads of ages were reckoned, not by arithmetical computation, but by a train of physical events -- a succession of phenomena in the animate and inanimate worlds -- signs which convey to our minds more definite ideas than figures can do, of the immensity of time.

Whether our investigation of the earth's history and structure will eventually be productive of as great practical benefits to mankind, as a knowledge of the distant heavens, must remain for the decision of posterity. It was not till astronomy had been enriched by the observations of many centuries, and had made its way against popular prejudices to the establishment of a sound theory, that its application to the useful arts was most conspicuous. The cultivation of geology began at a later period; and in every step which it has hitherto made towards sound theoretical principles, it has had to contend against more violent prepossessions. The practical advantages already derived from it have not been inconsiderable: but our generalizations are yet imperfect, and they who follow may be expected to reap the most valuable fruits of our labour. Meanwhile the charm of first discovery is our own, and as we explore this magnificent field of inquiry, the sentiment of a great historian of our times may continually be present to our minds, that "he who calls what has vanished back again into being, enjoys a bliss like that of creating." [23]

_______________

Notes:

1. Our miners have been left to themselves, almost without the assistance of scientific works in the English language, and without any "school of mines," to blunder their own way into a certain degree of practical skill. The inconvenience of this want of system in a country where so much capital is expended, and often wasted, in mining adventures, has been well exposed by an eminent practical miner. -- See "Prospectus of a School of Mines in Cornwall, by J. Taylor, 1825."

2. Cuvier, Eloge de Werner.

3. Cuvier, Eloge de Desmarest.

4. Journ. de Phys., vol. xiii. p. 115; and Mem. de l'Inst., Sciences, Mathemat. et Phys., vol. vi. p.219.

5. Journ. de Phys., tom. xxv. p. 191.

6. Ib. tom. xxxvii. part ii. p. 200.

7. Cuvier, Eloge de Desmarest.

8. Ed. Phil. Trans., 1788.

9. Playfair's Works, vol. iv., p. 75.

10. Playfair's Works, vol. iv. p. 55.

11. In allusion to the theories of Burnet, Woodward, and other physico-theological writers, he declared that they were as fond of changes of scene on the face of the globe, as were the populace at a play. "Every one of them destroys and renovates the earth after his own fashion, as Descartes framed it: for philosophers put themselves without ceremony in the place of God, and think to create a universe with a word." -- Dissertation envoyee a l'Academie de Bologne, sur les changemens arrives dans notre Globe. Unfortunately this and similar ridicule directed against the cosmologists was too well deserved.

12. See the chapter on "Des pierres figurees."

13. In that essay he lays it down "that all naturalists are now agreed that deposits of shells in the midst of the continents, are monuments of the continued occupation of these districts by the ocean." In another place also, when speaking of the fossil shells of Touraine, he admits their true origin.

14. As an instance of his desire to throw doubt indiscriminately on all geological data, we may recall the passage, where he says that "the bones of a reindeer and hippopotamus discovered near Etampes, did not prove, as some would have it, that Lapland and the Nile were once on a tour from Paris to Orleans, but merely that a lover of curiosities once preserved them in his cabinet."

15. The Task, book iii. "The Garden."

16. p. 577.

17. p. 59.

18. Introd. p. 2.

19. London, 1809.

20. I observe that, in a most able and interesting article "the Life of Galileo," recently published in the "Library of Useful Knowledge," it is asserted that both Galileo's work, and the book of Copernicus" Nisi corrigatur, "were still to be seen on the forbidden list of the Index at Rome in 1828. But I was assured in the same year, by Professor Scarpellini, at Rome, that Pius VII., a pontiff distinguished for his love of science, procured in 1818 a repeal of the edicts against Galileo and the Copernican system. He assembled the Congregation, and the late cardinal Toriozzi, assessor of the Sacred Office, proposed "that they should wipe off this scandal from the church." The repeal was carried, with the dissentient voice of one Dominican only. Long before this time the Newtonian theory had been taught in the Sapienza, and all catholic universities in Europe (with the exception, I am told, of Salamanca); but it was always required of professors, in deference to the decrees of the church, to use the term hypothesis, instead of theory. They now speak of the Copernican theory.

21. Theory of the Earth, vol. ii. p. 296; and Playfair's " Illustrations," note 16, p.352.

22. Werner invented a new language to express his divisions of rocks, and some of his technical terms, such as grauwacke, gneiss, and others, passed current in every country in Europe. Smith adopted for the most part English provincial terms, often of barbarous sound, such as gault, cornbrash, clunch clay, &c., and affixed them to subdivisions of the British series. Many of these still retain their place in our scientific classifications, and attest his priority of arrangement.

23. Niebuhr's Hist. of Rome, vol. i. p. 5. Hare and Thirlwall's translation.
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