Charles Lyell and Modern Geology

had been definitely concentrated for nearly five years, and for which he had been preparing himself during a considerably longer time. It placed him, before his fourth d

s "Origin of Species by Natural Selection," for that dealt only with one portion of geology-viz. with pal?ontology, while the method of the Principles affected the science in every part. For a brief interval, then, we may desert the biography of the author for that of the book-the parent for his offspring-and call attention to one or two topics which are more immediately connected with the book itsel

sued in January, 1832, and one of the second volume in the same month of 1833; these were all in 8vo size. A new edition of the whole work was published in May, 1834. This, however, took the form of four

ts of Geology"; a sixth edition of the "Principles," thus curtailed, appeared in three volumes 12mo, in June, 1840. The effect of the change was to restrict the "Principles" mainly to the physical side of geology-to the subjects connected with the morphological changes which the earth and its inhabitants alike undergo. Thus it made the contents of the bo

rate the effect which forces still at work had produced upon the earth's crust, and these strengthened the evidence which had been already advanced. Into the accounts of Vesuvius and Etna much important matter was introduced, the result of visits which, as we shall find, Lyell made in 1857 and 1858; the chapters relating to the vicissitudes of climate in past geological ages were entirely rewritten, together with that discussing the connection between climate and the geography of the earth's surface; and a chapter, practically new, was inserted, which considered "how far former vicissitudes in climate may have been influenced by astronomical changes; such as variations in the eccentricity of the earth's orbit, changes in the obliquity of the ecliptic, and different phases of the precession of the equinoxes." But the most important change was made in the later

n the lowest parts of the western basin of the Mediterranean. Samples also of the bottom had been obtained, and, in many cases, even dredgers had been successfully employed at these depths. Thanks to the skill of the mechanician, the way had been opened which led into a new fairyland of science. This was not, like some fabled Paradise, guarded by mountain fastnesses and precipitous ramparts of eternal snow; it was not encircled by storm-swept deserts, or secluded in the furthest recesses of forests, hitherto impenetrable; but it lay deep in the silent abysses of ocean-on those vast plains, which are unruffled by the most furious gale, o

he year in which the eleventh edition had appeared; and though she did not actually return till after Lyell's death, notes of some of her most interesting discoveries had been communicated from time to time to the scientific journals of this country. The edi

mposition, so that when the facts which he desired to cite had undergone no change, he very seldom found any to make in his language. Nevertheless, here and there, some small modification, a slight verbal difference, a trifling alteration in the order of a sentence, the insertion of a short clause to secure greater perspicuity, shows to how careful and close a revision the whole had been subjected. In the substance of the work, besides the excision of nearly one-third of the material and the complete reconstruction of the part relating to the antiquity of man and the origin of species, already mentioned, the following are the most important changes. The chapters which discuss the evidence in favour of past mutations of climate and the causes to which these are due, are rewritten and greatly enlarged. In the earlier editions, the effects of geographical changes were regarded as sufficient to account for all the climatal variations that geology requires; i

half a century enables us to understand it better at the present time; for the author, of course, had to deal with contemporary work and opinion only in a very indirect way. We may dismiss briefly the crude speculations of the earliest observers-those anterior to the Christian era-of which the author gives a s

ace had remained and would continue to remain, unaltered. But they had never compared attentively the results of the destroying and the 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, or of living species of animals and plants, with those belonging to former cond

ern race and an alien creed. The caliphs of Bagdad encouraged learning, and the students of the East became familiar by means of translations with the thoughts and questionings of ancient Greece and Rome. The efforts of their earliest investigators have not been preserved, but in treatises of the tenth century-written by one Avicenna, a court physician, the "Formation and Classification of Minerals" is discussed, as well as the "Cause of Mountains." In the latter attention is called to the effect of earthquakes, and to the excavatory action of streams. In the same century also, "Omar the Learned" wrote a book on "the retreat of the sea," in which he proved by reference to ancient charts and by other less dire

he deep where

t changes th

e long street r

ss of the c

trengthened on similar grounds by Frascatoro. He, however, not only demonstrated the absurdity of explaining these organic structures by the "plastic force of Nature"-a favourite refuge for the intellectually destitute of that and even a later age, but he also showed that they could not even be relics of the Noachian deluge. "That inundation, he observed, was too transient; it had 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." As Lyell truly remarks, "His clear exposition of the evidence would have terminated the discussion for ever, if the passions of man 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 difficulties raised by theologians, and the general preference for deductive over inductive reasoning, greatly impeded progress. It was not till the methods of the schoolmen yielded place to those of the natural philo

the minds of men, its place was taken by that which reg

posed to the imputation of disbelieving the whole of the sacred writings. Scarce any step had been made in approximating to sound theories since the time of Frascatoro, more than a hundred years having been lost in writing down the dogma

eaning though incompetent laymen echoed their cry; the more timorous among scientific men wasted their time in devising elaborate but futile schemes of accommodation between the discoveries of geology and the supposed revelations of the Scriptures; the stronger laboured on patiently, gathering evidence, strengthening their arguments and dissecting the fallacies by which they were assailed, until the popular prejudice should be allayed and men be calm enough to listen to the voice of truth. It was a long and weary struggle, which is now nearly, though not quite,

reasoning which commonly passed current for geological science. Chief and earliest among these men, Vallisneri, also an Italian, about a century before Lyell's birth, was clearsighted enough to see "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"; indeed, he was so far advanced as to attempt a general sketch of the marine deposits of Italy, with their organic remains, and to arrive at the conclusion that the oce

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 mountain

hed, if indeed it ever be, for many a long year to come. During the next half of the century progress was made, now in this direction, now in that; slowly truths were established, slowly errors dispelled; and as the close of that century approached, the foundations of modern geology began to be securely laid. A great impulse was given to the work, though to some extent the apparent help proved to be a real hindrance, by that famous teacher, Werner of Freiberg, in Saxony. His influence was highly beneficial, because he insisted not only on a careful study of the mineral character of rocks, but also on attending to their grouping, geographical distribution, and general

elled 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 became a ruling object of ambition in th

Werner, in fact, was a conspicuous example of a tendency, which perhaps even now is not quite extinct, to work too much beneath a roof and too little in the open

he Vivarais and Velay, in which he showed how the streams of basalt had poured out from craters which still remain in a perfect state. Desmarest also pointed out that in Auvergne "first came the most recent volcanoes, which had their craters still entire and their streams of lava conforming to the level of the present river courses. He then showed 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 crate

ning to sweep away everything before it. These were James Hutton and William Smith; the one born north, the other south of the Tweed. From the name of the former that of his friend and expositor, John Pl

ecord does not go back to the beginning, and that therefore any attempt to trace that beginning from geological evidence was vain. Most strongly, too, did they protest against the introduction of causes which could not be shown to be a part of the present economy. They never wearied of insisting that to the everyday workings of air, earth, and sea, must be our appeal for an explanation of the older revolutions of the globe. The fall of rain, the flow of rivers, the slowly crumbling decay of mountain, valley, and shore, were one by one summoned as witnesses to bear testimony to the manner in which the most stupendous geological changes are slowly and silently brought about. The waste of the land, which they traced everywhere, was found to give birth to soil-renovation of the surface thus springing Ph?nix-like out

h it might have obtained the strongest support, and have liberated itself from the bondage of deluges; in other words, of convulsive action, by which it was still fettered, for "it took no account of the fossil remains of plants and animals. Hence it ignor

er of superposition. So early as 1790, he published a "Tabular View of the British Strata," and from that time was engaged at every spare moment in constructing a geological map of England, all the while freely communicating the results of his researches to his brethren of the hammer. "The execution of his map was comple

"raised these departments of study to a rank of which they had never before been deemed susceptible. Their investigations had eventually 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 dwe

be forgotten, who were either less frequent visitors or more directly devoted to other studies. At this time geology was passing into a phase which endured for some forty years-the exaltation of the pal?ontological, the depreciation of the mineralogical side. If it be true, as it has been more than once remarked, that the father of the geologist was a mineralogist, it is no less true that his mother was a pal?ontologist; but at this particular epoch the paternal influence obviously declined, while that of the mother became inordinately strong. Wollaston and MacCulloch, indeed, were geologists of the old school; excellent mineralogists and petrologists (to use the more modern term) as accurate as it was possible to be with the appliances at their disposal, but among the younger men De la Beche, accompanied to a certain extent by Scrope and Sedgwick, was almost alone in following their lead. But although pal?ontology and stratigraphical geology as its associate were clearly making progress, the school of thought, of which Lyell became the champion, counted at this time b

e earth there have been long periods of comparative repose, during which the sedimentary strata have been continuously deposited, and short periods of paroxysmal violence, during which that continuity has been interrupted. (2) At each of these periods of violence or revolution in the state of the earth's surface, a great number of mountain-chains have been formed suddenly, and these chains, if contemporaneous, are para

had already become convinced, by his field-work in Italy and France, of the efficacy of existing forces to work mighty changes, if time were given, in the configuration of the earth's surface. This was George Poulett Scrope, a man of broad culture, great talents, and singular independence of thought, who had convinced himself of the errors of the Wernerian t

nclusion it was necessary to show that, even in historical times, considerable changes had occurred in the outlines of coasts, and that heat and cold, the sea, or rain and rivers-especially the last-had been agents of the utmost importance in the sculpture of cliffs, valleys, and hills. For both these purposes careful study, not only in Britain, but also still more in other regions, was absolutely necessary, and it was with them in view that Lyell undertook his journeys, from the time when his geological ideas began to assume a definite shape until the last volume of the "Principles" was published. By that date, as has been stated in the preceding chapters, he had made himself familiar in the course of his geological education with many parts of Britain, had laboriously investigated the more important collections and museums of France and Italy, and had carefully studied in the field the principal Tertiary deposits not only in these countries but also in Sicily and in parts of Switzerland and Germany. To obtain evidence bearing on the physical aspect of the question on a scale grander than was afforded by the undulating lowlands, or worn-down highland regions of Britain and the neighbouring parts o

TNO

t sixteen chapters, for the final one (dealing

eology," vol. i. p. 2

Memoriam

s of Geology,"

les of Geolog

les of Geolog

788, and in an enlarged form in 1795. Playfair's "Illustrati

Life of Murchis

les of Geolog

les of Geolog

l's summary: "Principle