Lyell, Charles

views updated May 17 2018

Lyell, Charles

(b, Kinnordy, Kirriemuir, Angus, Scotland, 14 November 1797; d. London, England, 22 February 1875)

geology, evolutionary biology.

Charles Lyell was the eldest child of Charles Lyell, Esq., of Kinnordy and the former Frances Smith, daughter of Thomas Smith of Maker Hall, Swaledale, Yorkshire. Both of Lyells parents had been born in London, where both his grandfathers were connected with the British navy. His paternal grandfather, also Charles Lyell, served as a purser on various ships and in 1770 entered into a partnership to supply His Majesty’s ships on the coast of North America. In 1778 he became secretary to Admiral John Byron during the latter’s disastrous expedition to America and the West Indies. In 1782 he purchased the estate of Kinnordy at Kirriemuir, in what was then the county of Forfarshire, Scotland, and retired to lead the life of a Scottish laird.

Lyell’s father matriculated in 1786 at Saint Andrews University and in 1787 at Peterhouse College, Cambridge, from which he was graduated B.A. in 1791. He thereafter studied taw at Lincoln’s Inn until he inherited the Kinnordy estate in Scotland on his father’s death in 1796. On 4 October 1796 he married Frances Smith at Sid mouth, Devonshire.

When Charles Lyell was less than a year old, his father left Scotland for the south of England, where, in the autumn of 1798, he took a long lease on Bartley Lodge at Lyndhurst, on the border of the New Forest in Hampshire. There Lyell spent his boyhood. Strongly interested in botany, his father collected rare plants in the New Forest and corresponded with James Sowerby, Dawson Turner, William Hooker, and other botanists. He also made regular trips to Scotland to supervise his estate.

In 1805 Lyell, aged seven, was sent to school at Ringwood, Hampshire, and in 1808 at Salisbury, In December 1808 he became severely ill with pleurisy, and during his convalescence at Bartley he began to collect insects and study their habits. In 1810 Lyell and his younger brother Thomas were sent to school at Midhurst, in Sussex. He left Midhurst in June 1815 and in February 1816 matriculated at Exeter College, Oxford, as a gentleman commoner. At Oxford he received the customary classical education based largely on the reading of Aristotle and other ancient authors, but in 1817 he took the course of lectures in mineralogy given by William Buckland and in 1818 attended Bucklands lectures in geology.

Since boyhood Lyell had been an enthusiastic amateur entomologist, and now Buckland aroused his interest in geology. In July 1817 Lyell visited his father’s friend Dawson Turner at Yarmouth, Norfolk, where he studied the effects of the interaction of the Yare River with the sea in forming the delta on which Yarmouth stood. In September 1817, while in Scotland with his father, he went with two college friends on horseback through the Highlands, along Loch Awe to Oban and thence by water to the island of Mull and to Staffa, famous for its columnar basalt formation. On Staffa, Lyell confirmed for Buckland that there were the broken ends of basalt columns in the roof of Fingal’s Cave, a fact which showed that the cave had not been formed by the erosion of an intrusive dike of softer lava, as had been suggested by Leopold von Buch. During the summer of 1818 Lyell accompanied his parents and sisters on a carriage tour through France, Switzerland, and the north of Italy, crossing the Jura and the Alps. In the Alps he observed the effects of glaciers and the destruction produced by mountain torrents.

On 19 March 1819 Lyell was elected to the Geological Society of London and in the same year to the Linnean Society. He was entered at Lincoln’s Inn, where in the autumn of 1819 he began to study law, reading in the office of John Patteson, the pleader. During the spring of 1819, however, when Lyell was studying for his degree examinations at Oxford, his eyes had begun to give him a great deal of pain and he found that he could not sustain the prolonged and intense reading needed for his legal studies. He got on as best he could with the help of a reading clerk, but in August 1820 set out with his father on a long tour of the Continent. They traveled through Belgium to Cologne and thence up the Rhine valley and south into Italy, where they visited Ravenna and Rome. Along the Adriatic coast of Italy Lyell observed how the rivers descending from the Apennines had created a coastal plain, and cities which were ports during Roman times were now five miles from the sea. After his return to London in November 1820, Lyell continued his legal studies, but in a more relaxed fashion.

During the summer of 1821 Lyell visited his old school at Midhurst, Sussex, and, becoming curious about the geology of Sussex, called on Gideon Mantell, a surgeon in Lewes, who had formed a collection of fossils from the chalk of the South Downs and the underlying strata of the Weald. They became close friends and pursued a common interest in the geology of southeast England. In April 1822 Lyell visited Winchelsea and Romsey, on the southeast coast, to study the series of strata below the chalk, since they were visible in the cliffs along the English Channel. In late June 1822 Lyell also visited the Isle of Wight, where he discovered that the sequence of strata below the chalk was the same on the Isle of Wight as on the coast of Sussex and that the formation on the Isle of Wight called the greensand by Thomas Webster was identical with the Reigate firestone and the marl rock of western Sussex. The formation in England called greensand by G. B. Greenough and W. D. Conybeare was identical, however, with a lower series of beds which Webster had called the ferruginous sand on the Isle of Wight. Lyell outlined the distinction between the formations now known as the upper and lower greensand in a letter to Mantell of 4 July 1822. He did not publish his findings, and the same observations were first published in a general study of the greensand by William Fitton in 1824, after he had seen Lyell’s letter to Mantell on the subject.

On 25 June 1823 Lyell arrived in Paris, where he spent the next two months. He studied French and attended free lectures on mining, geology, chemistry, and zoology. He met many French scientists, including Alexandre Brongniart, Georges Cuvier, and Constant Prévost, and the great German scientist and traveler Alexander von Humboldt, who was then living in Paris. With Prévost, Lyell studied the geology of the Paris basin and was influenced by Prevost to believe that the alternation of freshwater and marine formations could be explained naturally, without resort to catastrophes of unknown magnitude or cause. Prévost had found places where marine and freshwater fossils were mixed together, and he suggested that the basin had been at times a freshwater lake and at other times a great bay of the sea into which various rivers had emptied. The change from one state to another would have required only a relatively minor geological change in the barrier separating the Paris basin from the open sea, or in the level of the basin in relation to sea level. Prevost’s explanation of geological changes in the Paris basin was radically different from that of Cuvier, who had accounted for the alternation of marine and freshwater formations by suggesting violent incursions of the sea over the land. Prévost, a student of Lamarck, also held to the principle of “induction to deduce what has been from what is.”1

In Paris, Lyell took a broad and discriminating interest in French culture and institutions, but the scientific influence of Paris on him was most profound. He became aware of the depth and seriousness of French studies on natural history and geology, and in particular he became interested in freshwater formations.

In June 1824 Lyell entertained Constant Prévost when he visited England, and they went together on a geological tour of the southwest of England. During the late summer of 1824 Lyell worked at the geological mapping of his native county of Forfarshire in Scotland and made a detailed study of the marl deposits formed in its small freshwater lakes. This study provided the material for Lyell’s first scientific paper, “On a Recent Formation of Freshwater Limestone in Forfarshire … ,” which he began to read to the Geological Society on 17 December 1824. He found that modern freshwater marls were similar in their physical characteristics and contained the same types of fossils as the ancient freshwater marls studied by Cuvier and Brongniart in the Paris basin. In particular Lyell found that in certain circumstances a hard, dense limestone deposited in the Scottish lakes was exactly like certain ancient freshwater limestones of the Paris basin. Cuvier and Brongniart had believed that under modern conditions only soft, friable deposits formed in lakes; and Lyell showed that the distinction they had drawn between ancient and modern freshwater sediments was not valid.

In 1822 Lyell was called to the bar; and from 1825 to 1827 he was a practicing barrister, traveling on the Western Circuit, which included assizes at Winchester, Salisbury, Dorchester, Taunton, Exeter, and Bodmin. Although Lyell never derived any significant income from his legal practice, he valued his professional status as a lawyer because it freed him from many social demands upon his time. On circuit he had opportunities to study the geology of the southwest of England, and it was while on circuit during the summer of 1827 that he read Lamarck’s Philosophie zoologique. From 1823 to 1826 Lyell served as one of the secretaries of the Geological Society, and in 1826 he was elected a fellow of the Royal Society. In 1825 he published a paper on a dike of serpentine cutting through sandstone strata in Forfarshire.2 He also began to write articles for the Quarterly Review, His first article, published in December 1825, was a review of Thomas Campbell’s Letter to Mr. Brougham on the Subject of a London University; and the writing of it aroused Lyell’s interest in the state of university education in England. In June 1826 he published his second article, “On Scientific Institutions,” in the Quarterly Review; and in September 1826 his third article appeared, a review of the first volume of the second series of the Transactions of the Geological Society of London, The last article was in effect a review of the state of geology in 1826. Lyell discussed current knowledge of the regular succession of stratified formations and the many recent discoveries of fossils, especially of the skeletons of fossil vertebrates. In considering the forces that had brought about geological change, he thought it possible that, given sufficient time, geological causes now active, such as earthquakes and volcanic action, could have raised sedimentary strata from the bottom of the sea to the places they now occupy in hills and mountains. He thought it premature to consider that any unknown force would have been needed and that to postulate more powerful disturbing forces in earlier geological periods would tend to discourage geologists from studying those changes now going on. Lyell showed that older strata had been deposited during long periods of tranquil and orderly conditions, just as younger strata had, and that the elevation and bending of strata proceeded in much the same way in successive geological periods.

In June 1827 the Quarterly Review published Lyell’s fourth article, “State of the Universities,” an extensive and profound comparison of universities in England with those in Scotland and on the Continent. Lyell described the concentration of teaching in the colleges at Oxford and Cambridge; their attention to classical studies to the exclusion of modern languages, modern history, economics, political science, and natural sciences; and the fact that although the dons taught nothing but classics, they made almost no contribution to classical scholarship. He followed this original and comprehensive analysis of English university education with various suggestions for reform, some of which were implemented much later in the nineteenth century.

During the summer of 1827 Lyell wrote a review of George Scrope’s Memoir on the Geology of Central France (London, 1827), which was published in the Quarterly Review for October 1827, Scrope’s book aroused Lvell’s interest in the Auvergne district of France. In 1822 the discovery by Gideon Mantell of a river delta formation in the Tilgate forest be beneath the chalk in Sussex had suggested to Lyell the magnitude of the earth movements which could sink the land surface, represented by the Tilgate forest beds, beneath the deep ocean in which the chalk was deposited, and then elevate it again to form the high ridges of the Weald, He also realized that the outlines of the ancient land surfaces, even those contemporary with the younger Teniary strata of the Hampshire and London basins, had been completely obliterated. In contrast, the Auvergne, with its succession of ancient volcanic formations, was a geographically definable area since an early period in geological lime. In Auvergne there were lava flows from at least three successive periods of volcanic activity. The most recent extinct volcanoes still retained their cones and craters intact, with unbroken sheets of lava extending into the river valleys. Beneath these layers of lava were others which bore no relation to the existing cones. Still older were isolated masses of basalt capping outlying hills. In addition to volcanic rocks of successive ages there were in Auvergne thick formations of freshwater strata containing fossils of extinct animals. Thus, through geological periods long enough for great changes in organic life, the Auvergne had remained a region of volcanic mountains, valleys, and freshwater lakes. In its geological history.

In May 1828 Lyell set off for Auvergne to see its geology for himself. In Paris he joined Roderick Murchison and Mrs. Murchison, and they traveled south in Murchison’s light open carriage. During the next two months they traversed the volcanic mountains and freshwater formations of central France. Lyell was struck by the resemblance of the ancient freshwater sediments of Auvergne to the modern deposits he had studied in Scotland, Both contained such fossils as the seedpods of Chara (gyrogonites), Cypris, caddis fly larva cases (Phryganea), and freshwater shells. But he was also astonished by a Tertiary freshwater limestone in the Cantal, near Aurillac, which at first sight looked exactly like the English chalk, a much older marine formation. Lyell and Murchison observed the action of rivers in Auvergne in reexcavatmg river valleys after they had been filled by successive lava flows.

From the Auvergne, Lyell and Murchison descended into the Rhone valley at Montélimar and went south. On 9 August they were at Nice, where they paused for some weeks to rest and to allow Murchison to recover from an attack of fever. The effect of the tour thus far had been to suggest to Lyell many analogies between conditions during the geological past and those of the present. His enthusiasm for geology was raised to the highest pitch. Murchison now suggested to Lyell that he go on to the south of Italy and Sicily, where he would see younger strata and many instances of modern changes produced by the volcanoes of Vesuvius and Etna. Before he left London, Lyell had begun the manuscript of a geological book in which he pointed out analogies between ancient and modern conditions. The tour through France had provided him with numerous instances to amplify this work, and he decided to go on to gather even more information.

In Nice, Lyell learned from Giovanni Risso that the fossil seashells in the local marine Tertiary strata included about 18 percent of species still living in the Mediterranean. From Nice, Lyell and Murchison traveled east along the coast to Genoa. They then returned to Savona and crossed the Apennines to Turin, where Franco Bonclli, director of the museum of zoology, told them that the fossil shells of the nearby hill of Superga differed from those of the subapennine beds but corresponded closely to the shells of the Bordeaux Tertiary formation in France. Tney differed also in the proportion of fossil shells belonging to still-living species. Lyell now formed the idea of classifying Tertiary formations according to the proportion of living species among their fossils. Furthermore, because he considered that volcanoes and earthquakes were associated with the uplift of strata, he thought that as he approached the active volcanoes of Vesuvius and Etna, he would find younger and more recently uplifted strata containing Jarger proportions of still-living species.

Murchison and Lyell traveled together as far as Padua, where they parted, Lyell going south through Italy while Murchison turned north on his way hack to England. Lyell examined collections of fossils at Parma, Bologna, Florence, and Siena and made his own collection of subapennine shells. From Naples he went to the island of Islands, where he collected some thirty species of fossil shells, all belonging to species living in the Mediterranean, from marl strata at an elevation of 700 feet on the side of the extinct volcano of Epomeo. Up to this point Lyell’s discoveries entirely fulfilled his expectations. He thought the strata on Ischia had been elevated very recently and represented more or less contemporary deposits of the Mediterranean sea bottom. He assumed that soft marls containing only living species of shells must be very recent. He had found that the strata in the vicinity of volcanoes, and in an area where earthquakes were frequent, contained fossil shells of the same species as were still living in the Mediterranean. In Naples, Lyell studied Vesuvius and the temple of Serapis at Pozzuoli, which showed evidence of both elevation and subsidence of the land during historic times.

On 16 November 1828 Lyell crossed to Messina, Sicily, and rode on muleback south along the coast to Taormina. He visited the Val del Bove and from Nicolosi climbed Mount Etna. He was deeply impressed by the enormous size and great age of Etna, which he was convinced had been built up by a long series of volcanic eruptions like those still going on. His first doubts about the necessary recentness of strata containing living species of fossils may have arisen from a bed of clay above Catania that contained many modern Mediterranean shells. When he looked back at Etna from the ridge above Primosole, he saw that the enormous mass of the volcano appeared to rest, as though on a platform, on the plateau formed by the clay hills above Catania, so that the clay strata appeared older than the mountain.

In Lentini, Lyell saw for the first time the hard white limestone of the Val di Noto; it puzzled him because, while he thought it ought to be recent, it contained only the casts of shells, like an ancient Secondary limestone. As he rode down the valley of the Anapo River toward Syracuse, Lyell saw the white limestone exposed in the cliffs to a thickness of more than 800 feet. At the foot of the white limestone escarpment at Floridia, near Syracuse, were strata of calcareous sandstone. On the south side of the harbor of Syracuse, Lyell found, apparently beneath the white limestone—and therefore still older—strata of soft marl containing many perfect fossil shells, some still retaining their colors and all belonging to species still living in the surrounding Mediterranean. He was, however, uncertain of the relation or the marl to the white limestone until he reached Girgenti (now Agrigento), where he found strata of blue clay containing shells overlain by strata of calcareous sandstone identical with that at Floridia.

Astonished at what he was finding, and doubting whether he had observed correctly, Lyell explored the interior of Sicily until at Castrogiovanni (now Enna) he found all the strata of the Sicilian formation, from the white limestone of Lentini down through sandstones and marls to the blue clay of Syracuse, containing living species of shells with their original colors, all exposed in order in one immense escarpment. For Lyell the discovery that the white limestone, containing only casts and impressions of shells, was a very recent formation, had the force of revelation. It meant that the characteristics of a rock stratum were determined not by its geological age but by the conditions under which it was laid down, and these conditions had recurred again and again in successive geological periods. In Sicily, Lyell saw too that volcanic activity had gone on gradually and uniformly, interspersed with periods of rest, through an immense extent of time. Finally, he saw that the assemblage of shell species now living in the Mediterranean constituted a very old fauna, which had changed very little during the immense time required to deposit the stratified rocks of Sicily and to elevate them into hills of rounded and worn outline.

Because Lyell saw in Sicily a continuity between the fauna living in the Mediterranean and its fossil ancestors preserved in the rocks, he realized that the conditions under which both lived must be analogous. Therefore conditions during past geological ages must have been essentially similar to modern conditions on the earth’s surface, and the forces which brought about geologic changes must have been the result of processes similar to those going on at the present time. Fired with such new ideas, Lyell set out for England in January 1829, determined to rewrite his book to see how far he could “explain the former changes of the earth’s surface by causes now in operation.” He was now certain that the Tertiary formations represented a much greater period of time than he had dreamed and that the strata of the Paris basin, of the hill of Superga at Turin, of the subapennine hills, and of Sicily were not parallel and contemporary formations but represented different and successive periods of geological time.

In Turin, Lyell discussed his Sicilian results with Bonelli, and in Geneva he obtained from August in de Candolle information on the geographical distribution of plants. In Paris, which he reached on 14 February 1829, Lyell called on Jules Desnoyers, who in 1825 had shown that the Tertiary formation of the Loire valley was younger than that of the Paris basin. When Lyell told Desnoyers of his Sicilian discoveries and his opinion that the various Tertiary formations were of different ages and could be arranged according to the proportion of living species among their fossils, Desnoyers said that he himself had come to similar conclusions and that Gerard Paul Deshayes, who possessed a large collection of fossil shells, had also decided that Tertiary formations might be arranged in a chronological series on the basis of differences in their characteristic groupings of fossil shell species. Lyell immediately consulted Deshayes, who told him that on the basis of their fossil shells, Tertiary formations might be distinguished into three successive geological periods. Lyell then asked Deshayes to prepare a catalog of fossil shells from all the Tertiary formations of Europe.

Lyell returned to London on 24 February 1829, and from then until the beginning of June 1830 he wrote and saw through the press the first volume of his Principles of Geology. It was published by John Murray in July 1830 (not January, as stated in later editions of the Principles) and created an immediate sensation. In it Lyell first discussed the historical development of geology and then treated the principles of geological reasoning. He argued that the order of nature in the past was uniform with that in the present and, therefore, that the geologist should always try to explain geological phenomena by analogy with modern conditions. The greatest difficulty he had to overcome was the clear evidence for a warmer climate during past geological epochs even in high northern latitudes, such as those of Great Britain. To account for the changes in climate which had occurred between past geological epochs and the present, Lyell studied the factors which determine climate in different parts of the world at the present time. He showed how not only local climate, but even worldwide climatic conditions, depend on the pattern of distribution of land and sea and would, therefore, be altered by changes in their distribution. An increase in the proportion of land near the equator, and of ocean area toward the poles, would tend to create a warmer world climate and vice versa.

Lyell surveyed the full range of processes which at present are altering the earth’s surface—the eroding effects of running water in streams and rivers and of waves along the seacoast, the accumulation of sediments in deltas and on the sea bottom, and the cumulative effects of earthquakes and volcanoes in elevating the land. He showed that even the largest volcanoes, such as Vesuvius and Etna, were the product of a long series of eruptions distributed through immense periods of time, and the eruptions were never greater nor more frequent than in historic times. Lyell emphasized repeatedly that the magnitude of the geological changes which had occurred during the past was not a reason to postulate extraordinary convulsions or catastrophes. The greatest changes could be accomplished by ordinary geological processes acting gradually, if they were given sufficient time.

Lyell sought to separate geology from cosmology and refused to consider the question of the origin of the earth, or its state when first formed. Furthermore, he considered it unscientific to attempt to explain otherwise puzzling geological phenomena by reference to the origin of the world. In the succession of geological formations and geological changes Lyell saw an unending vista of uniform conditions on the earth’s surface, as stable as those that exist today, and of geological processes ceaselessly at work. The principle of the uniformity of the “course of Nature” throughout the history of the earth gave significance to every feature of the present natural world for the understanding of events in the past. The geologist therefore must study all changes now occurring on the earth, because these changes, daily at work, may enable him to understand otherwise puzzling geological phenomena of the past.

During the summer of 1830 Lyell made a geological expedition to the Pyrenees, followed by several weeks of study of Tertiary shells with Deshaycs at Paris. When he returned to London on 9 November, half the edition of the first volume of the Principles was already sold. During 1831 he wrote the second volume, which was published in January 1832. In this volume Lyell considered the changes which had occurred in the living world through geological time. His studies on Tertiary shells had already shown him that as one proceeded from older to younger strata, the proportion of fossils belonging to extinct species declined gradually while that of living species increased. Thus, throughout the Tertiary period species of shells had become extinct, one by one, to be replaced, one by one, by new species. The continuity thus revealed in the living world, accompanied by gradual change, was in sharp distinction to the apparently abrupt changes in the forms of animal life observed in the secondary strata of France and England. Lyell pointed out that all the species of mammals living when the present assemblage of marine mollusks had become established in the sea had since become extinct. Thus the land mammals, which were subject to many more vicissitudes than marine forms, became extinct more rapidly.

To account for extinction Lyell showed that the life of each species was dependent upon the continuance of a certain set of physical conditions in its environment. Geological processes, however, were steadily tending to alter these conditions, both locally and over wide regions. Thus the possible habitats for a species were steadily shifting and sometimes were obliterated. Lyell also showed that the life of a species was at the same time dependent upon a multitude of relationships with other species living in the same area. There was severe competition between species for living space, so that sometimes a species might become extinct simply because it could not contend successfully with others. And the extinction of one species would drag in its train the extinction of others which were dependent upon it. Similarly, the increase and spread of a successful species would force many others into extinction. Yet the geographical distribution of species showed that every species had tended to spread outward from its geographical center of origin. Lyell thus showed that the living world of plants and animals was in a state of dynamic balance and that the fluctuations of the balance of nature would themselves steadily tend to produce the extinction of species.

Lyell’s argument required the assumption that species were real, definite, and stable entities. If species were infinitely plastic, or had no real existence, as Lamarck had supposed, they need never become extinct but could simply adapt themselves endlessly to varying conditions. Lyell therefore began his discussion of species with a systematic examination and criticism of Lamarck’s theory.

Lyell also used evidence drawn from the geographical distribution of plants and animals to show that each species appeared to have arisen in a single center, from which it had spread. The area of its distribution was limited by geographical barriers of different kinds. Places with similar altitude and climate on two isolated continents have entirely different sets of species, although the two sets of species may have adapted in similar ways to similar conditions. Lyell showed that each species had arisen at a particular place and at a particular time in geologic history, and had persisted for a certain period, at the end of which it became extinct and was replaced by a new species.

Lyell left the species problem at this point. He had shown that the emergence of new species was a steady process In geologic history that was needed to compensate for the equally steady process of extinction, but he did not attempt to say how new species emerged. His readers were thus left in suspense. Privately, Lyell had pondered the question of the origin of species and was certain that they emerged by some natural process, but he had no explanation to offer. Although he was fascinated by Lamarck’s theory, he felt certain, on scientific grounds, that it was false.

In 1831 Lyell was appointed professor of geology at King’s College, London, and in May and June 1832 delivered his first course of lectures on geology, a course which was widely attended by members of the public. On 12 July 1832, at Bonn, Germany, Lyell married Mary Elizabeth Horner, aged twenty-three, daughter of Leonard Horner, a fellow of the Geological Society and from 1828 to 1830 warden of London University. On their return to London after a wedding trip up the Rhine valley and through Switzerland and France, Lyell took a house at 16 Hart Street. Mary Lyell, who read German and French fluently, assisted Lyell in his reading and geological work at home and accompanied him on almost all his geological travels abroad. She became an accomplished conchologist and, because of the weakness of his eyes, often wrote Lyell’s letters for him.

In the third volume of the Principles, published in 1833, Lyell attempted to answer some of the criticisms of his doctrines provoked by the first two volumes. The opening chapter is a splendid defense of the point of view to which William Whewell had already attached the name “uniformitarian.”, Lyell argued that the natural order of the past was uniform with that of the present; the same physical laws held true and the same kinds of processes occurred. The geologist should, therefore, attempt to explain geological phenomena by analogy with modern processes. The apparent difficulty in doing so was chiefly a result of ignorance of the nature and extent of geological changes now going on. The remainder of the volume was an application of the doctrine of uniformity and the use of modern analogies to the problems of Tertiary geology. Lyell introduced his classification of Tertiary formations into four successive epochs and the terms Eocene (Gr.ήως, dawn; kαΐνος recent), Miocene (Gr.μ∊ℓως less;kαΐνος recent), and the older and newer Pliocene (∊̉ον, more, larger kαΐνος recent) to designate them. In the coinage of these terms he was assisted by William Whewell, who suggested the common root kνΐνος Lyell’s classification showed that the Tertiary formations made up a series of strata enormously greater than had previously been suspected and represented a period of time correspondingly great. Lyell included, as an appendix to the third volume, Deshayes’s tables of more than 3,000 species of Tertiary fossil shells.

Besides establishing a new era in geology, the Principles became a lifework for Lyell. He continued to revise it and brought it out in twelve successive editions. The twelfth edition was corrected by him but appeared after his death. The second edition of a corrected version of the first and second volumes, published in May 1832 and January 1833, respectively, before the appearance of the third volume in May 1833. In May 1834 he published a new edition of the whole work, called the third edition, in four small volumes, dividing the material in the three volumes of the first edition into four books but omitting Deshayes’s tables of Tertiary shells. While continuing to revise and add to his text, Lyell retained the format of four small volumes for the fourth edition, which appeared in June 1835, and the fifth edition, which appeared in March 1837.

In July 1838 Lyell published his Elements of Geologyin one volume. Although the Elements was intended to be a brief descriptive work and not theoretical, in writing it Lyell took for granted the theoretical viewpoint he had already established in the Principles. Thus Lyelfs Elements was the first modern textbook of geology written on the assumption that geological phenomena could be explained completely in terms of natural and knowable causes.

When Lyell came to prepare the sixth edition of the Principles, he removed from it the discussion of Tertiary formations in book IV, in order to transfer all purely descriptive geology to a second edition of the Elements. He also transferred four chapters dealing with various theoretical questions from book IV to book I in order to retain them in the Principles. Lyell was anxious that the Principles and the Elements should not overlap in their subject matter. In addition he developed, in chapter 10 of book I, a theory that erratic boulders had been transported by icebergs; and in chapter 11 he presented evidence that volcanic action had occurred in all geological periods with ut the same intensity as at present. Lyell thus established in the sixth edition of the Principles, published in two volumes in June 1840, the plan of organisation to which he would adhere through the seventh edition (February 1847), the eighth edition (May 1850), and the ninth edition (June 1853). The seventh through ninth editions were each a single large octavo volume. After 1853 Lyell did not revise the Principles until 1865, when he undertook a major reorganization of the book.

The second edition of the Elements appeared in July 1841. With the inclusion of the chapters on Tertiary formations and other additions, it had grown from twenty-five to thirty-six chapters in two volumes. In the third edition, published in January 1851, Lyell changed the title to A Manual of Elementary Geology but did not alter the basic plan of the book. It remained the Manual in the fourth edition of January 1852 and the fifth edition of February 1855. For the sixth edition, however, published in January 1865, Lyell returned to the original Elements of Geology,

Lyell took great trouble to provide both the Principles and the Elements with maps, diagrams, and illustrations. He had numerous drawings of fossils made and transferred to woodcuts or engravings that were often of unusual beauty. As a rule each new edition of his work contained additional illustrations, Lyell took equal pains with his prose. The Elements is a model of simple, lucid exposition, while in the Principles he cultivated a disarming and entrancing style of great persuasive power. Lyell used visual images, analogies, and metaphors to help the reader envision the past history of the earth.

From 1834 to 1836 Lyell was president of the Geological Society of London. During June and July 1834 he traveled alone to Sweden to determine whether the rising of the land there, a phenomenon reported by a number of writers, were real of not. Lyell found that the evidence for a gradual and imperceptible, but steady, rise of the land in northern Sweden was clear and inescapable. On 27 November and 18 December 1834 he presedent the results of his Swedish tour to the Royal society of London as the Bakerian lecture.

In October 1836 Charles Darwin returned from the Beagle voyage, and a warm friendship soon sprang between him and Lyell. Darwin had taken Lyell’s Principles with him on the Beagle, and in South America he had discovered that the whole southern part of the continent had undergone a recent elevation in gradual and successive stages. On 7 March 1838 Darwin presented to the Geological Society a paper tn which he connected the phenomena of earthquakes and volcanic action in South America to show the elevation of the Andes and of the whole had been brought about gradually by the cumulative effect of repeated earthquakes and volcanic eruptions. Such a large-scale example of the action of modern causes provided Lyell with very welcome support for the theory of geological uniformity, for which he was still contending against eatastrophist opponents. Lyell was also deeply impressed by Darwin’s theory of the origin of coral reefs and atolls by gradual subsidence. Darwin and Lyell met most frequently from 1836 to 1841, when Darwin was living in London. After Darwin moved to Downe, Kent, he and Lyell corresponded regularly and met occasionally in London. From time to time the Lyelis went to Downe to spend several days with the Darwins, and during these visits Lyell usually took work with him.

In 1837 Lyell became involved in a controversy Edward Charlesworth over the classification of the crag, a Tertiary formation of Norfolk. In 1835 Charlesworth had correctly distinguished the red crag from the older coralline crag; but Lyell had thought that because there were 150 species of shells common to the two formations, they must belong to the same geological period. He suggested that the two deposits had been laid down contemporaneously in different parts of the same sea. Charlesworth then attacked the basis for Lyell’s classification of Tertiary formations. He pointed out the uncertainty in the discrimination of species and cited the opinion of some naturalists that almost all species of crag fossils were extinct. Because of the uncertainty whether fossil shells were identical with living forms or belonged to extinct species, Charlesworth argued that Lyell’s system classification based on the proportion of living to extinct species in a formation was unreliable.

To find answers to the questions raised by Charlesworth, Lyell made three geological tours of the crag, in April 1838 to Suffolk and in July 1838 and June 1839 to Suffolk and Norfolk. He found that Charlcsworth was right in considering the coralline crag to be an older formation than the red crag, but after an exhaustive study of crag fossil shells he also found that the percentage of living species in the crag formations confirmed Charlesworth’s geological findings instead of contradicting them. The coralline crag contained only 19 percent living species, while the red crag contained 30 percent and the Norwich crag, which Charlcsworth considered a still younger formation, contained between 50 and 60 percent living species of shells. Ironically, therefore, Charlesworth’s conclusions were upheld by the very system he had attacked. The crag question also caused Lyell to study intensively the range of variation, through time, of species of Tertiary fossil shells and to compare the opinions of the two leading fossil conchologist Europe, Heinrich Beck and Desha yes, on the identity of crag shell species.

On 20 July 1841 the Lyells sailed for America, where they remained until August 1842. After landing at Boston, Lyell visited the geologists of the New York State Geological Survey at Albany and the Lyells traveled through western New York, accompanied by James Hall. Deeply impressed by Niagara Fails, Lyell collected evidence to show that the falls were receding steadily toward Lake Erie and that the Niagara gorge had been produced by the gradual recession of the falls from the face of the escarpment at Queenston, Ontario. During October and November 1841 Lyell delivered the Lowell lectures in Boston. In December the Lyells traveled to the South, Lyell studied the Tertiary formations of the coastal plain in Virginia, the Carolinas, and Georgia. On their return northward Lyell gave courses of geological lectures in Philadelphia and New York, attended the meeting of the American Association of Geologists and Naturalists at Boston in April 1842, and then made a tour of the Ohio valley, Lake Erie, Lake Ontario, and the St. Lawrence River valley. He studied the succession of terraces around Lake Erie and Lake Ontario; and in Montreal and Quebec and at Lake Champlain he collected, from deposits of clay several hundred feet above sea level, fossil seashells belonging to Jiving Arctic species. During July and August 1842 Lyell spent a month studying the coal formation of Nova Scotia. He showed that the gypsumbearing strata were part of the lower Carboniferous formation rather than the upper.

At Pictou, Nova Scotia, Lyell met John William Dawson, then aged twenty-one and newly returned from a year of study at the University of Edinburgh, who accompanied him on several geological expeditions, Lyell encouraged Dawson to prepare papers to send to the Geological Society of London and thereby launched Dawson on his career as a geologist. Lyell was a sympathetic and perceptive observer of the United States and Canada and made a number of warm friends among Americans, who were impressed by Lyell’s geological knowledge and universal curiosity but sometimes bewildered by his absentmindedness and odd mannerisms. Invariably they were charmed by winning manners of Mary Lyell, was eqaully at ease in mansion or log cabin, in steamboat, railway car, or stagecoach, and always cheerful and uncomplaining, whatever mishaps or rdships she might suffer. On her part Mary Lyell ig affection for America. During the Civil War, when the United States was very unpopular in England, she defended the cause of the Union and befriended the United States ambassador, Charles Francis Adams, when he was subjected ostracism in London.

In 1845 Lyeil published his Travels in America a work unusual among descriptions of America by British travelers in its fairness and insight, and incorporating much discussion of the geology of North America. He included a geological map of eastern North America from the Gulf of St. Lawrence to Florida and Texas, based on the published works of twenty-six authors as well as on his own travels. In discussing American colleges Lyell was also led to discuss English university education because, he said, in trying to explain it to Americans he himself had become more aware of its unusual nature, Lyell followed up his criticisms of the English universities helping to obtain the establishment of a royal j mission on the universities.

In September 1845 Lyell returned to the United States, again to give the Lowell lectures in Boston. He and his wife first traveled to Maine and through the While Mountains of New Hampshire. After Lyell had delivered his course of lectures, the Lyells set off in December on a long tour through the South, stopping for two weeks in January 1846 with Hamilton Couper at Hopeton plantation, on the Altamaha River in Georgia. From Savannah, Georgia, they went to Claiborne, on the Alabama River, where Lyell collected fossils, then by steamboat to Mobile. From Mobile they went up the Tombigbee River to Tuscaloosa, to visit the Alabama coal field. Returning to Mobile, they continued by steamboat to New Orleans, where Lyell made an expedition to the mouth of the Mississippi River to study the growth of its delta. From New Orleans the Lyells went up the Mississippi and Ohio rivers by steamboat, and overland across Pennsylvania to Philadelphia. On 1 June 1846 they sailed for England. Jn 1849 Lyell published an account of this tour in his Second Visit to the United States.

In October 1846 the Lyells moved from 16 Hart Street to a larger house at 11 Harley Street (now 73 Harley Street). In 1848 Lyell was knighted, and in 1849 he was reelected president of the Geological Society of London. In this capacity he gave evidence before the Oxford University Commission, and by this and other means he was active in the reform of the universities and the introduction of science into university education. His books on America attracted the attention of Prince Albert, and he served as one of the royal commissioners for the Great Exhibition of 1851.

In August 1852 the Lyells sailed for Halifax, Nova Scotia, where Lyell went with J. W, Dawson to study the great fossil cliff at South Joggins. On this occasion they found inside the trunk of one of the upright fossil Sigiliaria trees of Joggins the skeleton of a reptile, later described by Richard Owen and named Dendrerpeton acadianum. Since the first air-breathing animal was discovered in the coal only in 1844, Dendrerpeton was one of but three or four fossil reptiles then known from the Carboniferous period. From Nova Scotia the Lyells went to Frederic ton, New Brunswick, where they were guests of Sir Edmund Head, the governor, and thence to Boston, where Lyell delivered the Lowell Lectures during the autumn of 1852. In December they returned to London. In June 1853 Lyell made a fourth visit to the United States, to represent, with Lord Ellesmere. the Royal Commission for the Exhibition of 1851 at the New York Industrial Exhibition of 1853; he returned to London at the beginning of August.

In December 1853 the Lyells sailed to Madeira, accompanied by Mr. and Mrs, Charles Bunbury, to spend several months studying the volcanic geology of Madeira and the Canary Islands. On Madeira, Lyell met a young German naturalist, George Hartung, who had come there to recover from consumption. Hartung joined Lyell in his geological expeditions and in the collection of specimens. Lyell was deeply impressed by the distinctive flora of these oceanic islands. On Madeira, at an elevation of about 1,000 feet above sea level, he discovered a bed of lignite containing fossilized leaves of plants similar to those of the modern forests of Madeira. The fossil plants showed that Madeira had existed as a land surface, and probably as an isolated oceanic island, since the Miocene. In the light of their long geological history as isolated islands, the zoology of the islands was also remarkable. They possessed no native mammals but contained an unusual number of insect species, especially of beetles; and many of the species were peculiar to individual islands. The species of land shells were even more remarkable. There were seventy-seven species on Madeira and fifty-five species on Pôrto Santo, but only nine species were common to the two islands, although they are only thirty miles apart.

The Lyells returned to England in March 1854. Until February 1855 Lyell was occupied in preparing the fifth edition of the Manual. He then visited Berlin and during the summer made a long visit to Scotland, In November 1855 Hartung came to London, and Lyell and he began to go over their collections from Madeira and the Canary Islands. The remarkable number of distinct species of insects and land shells —a pattern of geographical distribution of species similar to that which Charles Darwin had observed in the Galápagos Islands twenty years earlier—impressed Lyell as bearing directly on the question of the origin of species. On 26 November 1855 Lyell read an article by A. R. Wallace, “On the Law Which Has Regulated the Introduction of New Species,” in the Annals and Magazine of Natural History for September 1855. Wallace presented evidence from paleontology and from the geographical distribution of plants and animals to show that “Every species has come into existence co-incident in both space and time with a preexisting closely allied species.” Wallace’s paper seemed to express very aptly the meaning of the distribution of both fossil and living species in Madeira and the Canary Islands; and Lyell made extensive notes on it in a notebook devoted solely to the species question, the first of what would ultimately be seven such notebooks. Through the winter of 1856 Lyell continued to study Madeiran and Canary species, and he began to investigate the question of how species might migrate across areas of ocean to colonize islands.

On 13 April 1856 the Lyells went to Downe, Kent, to spend four days with the Charles Darwins. On the morning of 16 April, Darwin explained to Lyell his theory of the origin of species by natural selection. Lyell had been aware for many years that Darwin believed in the transmutation of species; but he now learned, apparently for the first time, the details of Darwin’s theory to account for the process of transmutation, Lyell immediately urged Darwin to publish his theory, a step which Darwin was reluctant to take because he thought that it could not be understood, or appreciated fully, except within the framework of a broad array of connected biological and geological evidence. During the summer of 1856. however, Darwin began to write on the relationship of the geographical distribution of species to geological history. In October 1856 Darwin decided that he could not publish a brief sketch of his theory and began to write the large work on which he was still engaged in June 1858, when he received from Alfred Russel Wallace the manuscript of Wallace’s paper containing the theory of natural selection.

The species of Madeira and the Canary Islands, together with Darwin’s theory of natural selection, caused Lyell to accept at least tentatively the possibility of the transmutation of species. In 1857 a series of discoveries of fossil mammals in the Purbeck strata showed that a rich mammalian fauna had lived during the Secondary period, in what had been considered exclusively an age of reptiles. This caused Lyell again to doubt whether there had been a genuine progressive development of animal life through geological time. In 1858 the publication of the Darwin-Wallace papers on natural selection renewed Lyell’s interest in the species question. From 1858 to 1861, when he began to write the Antiquity of Man, Lyell made many entries in his species journals and corresponded frequently with Darwin.

In October 1857 Lyell revisited southern Italy and Sicily, where he had not been since 1828, to make a fresh study of the structure of Vesuvius and Etna. In 1853–1854, in his study of Madeira and the Canaries, made with Hartung, Lyell had become convinced that the evidence on which Leopold von Buch had founded his theory of craters of elevation (1825) was completely fallacious. According to Buch’s theory, the volcanic rocks forming such islands as Tenerife and Pal ma had been formed originally as horizontal sheets of lava which had later been up heaved in a great convulsion to create the cones and craters of their modern volcanoes. Buch beheved that liquid lavas could not solidify to form sheets of solid ro on the steep slopes where they now occurred. Therefore, they must have been solidified in a horizontal position and later up heaved. In 1834 Élie de Beaumont, in a paper on Mount Etna, argued that the solid beds of lava in the Val del Bove, inclined at angles of 28° and more, resembled portions of modern lavas that flowed over ground almost level or inclined at no more than 3°. Geologists who accepted Élie de Beaumont’s conclusions were forced to believe that all modern volcanoes had acquired their conical form by later upheaval of their beds of lava.

In 1853–1854, on Madeira and Palma, Lyell had seen modern lavas forming sheets of solid rock and inclined at angles of 15° to 20° but showing no sign of any disturbance in position. In 1855 Hartung had also observed on Lanzarote in the Canaries a solid basaltic lava on a slope of 30°. In 1857 Lyell found on Etna lavas which had solidified on steep slopes of from 15° to 40° in inclination. The lavas formed continuous sheets of rock alternating with layers of loose scoriae above and beneath them. Lyell reported these results to the Royal Society on 10 June 1858, and in September and October 1858 he returned to Etna to make a more thorough study of its structure. He found that Etna had neither a linear axis nor a single center of upheaval. Instead, he found two earlier centers of eruption in the Val del Bove. From each center the beds of lava sloped away in all directions, but beds of lava arising from Etna’s modern center of eruption had flowed over and buried those from the earlier centers. Lyell considered this to be decisive evidence against the crater-of-elevation theory because “although one cone of eruption may envelope and bury another cone of eruption, it is impossible for a cone of upheaval to mantle round and overwhelm another cone of upheaval so as to reduce the whole mass to one conical mountain.”3 He concluded that the conical form of Etna, as of all volcanoes, was entirely the result of the long-continued process of volcanic eruption.

In June 1858 Charles Darwin consulted Lyell about Alfred Russel Wallace’s paper on natural selection, which he had just received, and Lyell and Joseph Hooker together presented Darwin’s and Wallace’s papers on natural selection to the Linnaean Society on 1 July 1858. In May 1859 Joseph Prestwich announced to the Royal Society that he had found, at St. Acheul near Abbeville, France, a.flint implement, the product of human workmanship, embedded in place in ancient river gravel Prestwich’s discovery, which established the geological age of the flint implements described earlier from Abbeville by Boucher de Perthes, was clear evidence that man had lived in Europe as far back as the later Pliocene and, therefore, far longer than had previously been thought. In July 1859 Lyell went to Abbeville and Amines to see for himself the places where flint implements had been found and continued to pursue the question of the antiquity of man, which he saw was related to that of the origin of species.

During 1860 and 1861 Lyell studied evidence of the early existence of man in Europe; and in 1862 he began to write The Geological Evidences of the Antiquity of Man, which was published in February 1863. In the Antiquity of Man Lyell discussed the state of knowledge concerning the prehistory of man, including the discovery of stone tools, the definition of the Bronze and Stone ages, the shell mounds of Denmark, and the Swiss lake dwellings. He gave a particularly thorough account of the discovery in 1857 of the skeleton of a man in a cave at Neanderthal, Germany, because the skull of the Neanderthal man, although unquestionably human, showed heavy eyebrow ridges like those of apes. In considering the origin of man, Lyell argued that if all races of man were descended from a common ancestry, as he believed they were, then it would have required a very long period of time for the gradual formation of such distinct races as the Caucasian, Mongolian, and Negro. If the different races of man were descended from a common ancestry, however, Lyell thought it equally probable that closely related species of animals and plants were likewise descended from a common parentage, He then reviewed his own 1832 analysis of Lamarck’s theory and said that while he had disagreed with Lamarck’s view of the transmutation of species, he had agreed with Lamarck “in believing that the system of changes now in progress in the organic world would afford, when fully understood, a complete key to the interpretation of all the vicissitudes of the living creation in past ages.”4 Lyell described Darwin’s and Wallace’s theory of the indefinite modification of species by natural selection and gave a brief abstract of some of Darwin’s arguments in the Origin of Species. He accepted Darwin’s theory as providing a clear explanation of many biological and geological phenomena previously puzzling, but did not make any declaration of his own adherence to the theory.

In the Antiquity of Man, however, Lyell, in the manner of a barrister, presented to the reader a broad array of evidence which indicated that man had evolved gradually from lower animals over an immense period of time, that species had been modified one into another, and that the modification had probably been produced by natural selection. He compared the gradual divergence of the various European languages from a common root language to the gradual divergence of species. By presenting evidence without drawing conclusions from it, Lyell kept the reader’s attention on the evidence and required him to draw his own conclusions. Lyell thus made the question of the origin of man and other species one of evidence rather than of doctrine. He kept his readers in suspense to the end of the book and induced them to consider the meaning of the evidence for themselves. Lyell thus gave Darwin powerful support in the controversy following the publication of the Origin of Species. Darwin, however, expressed disappointment that Lyell did not make a clear statement of his own opinion on the origin of species.5. In reply Lyell said that he had expressed his opinion fully “so far as my reason goes, and farther than my imagination and sentiment can follow.”6 Lyell seems to have felt a particular revulsion toward the idea that man was descended from animals and to have thought that the origin of the human intellect required a special explanation. At Darwin’s urging he amended his statements concerning species in a later edition of the Antiquity of Man but remained hesitant.

On 30 November 1864, at the anniversary meeting of the Royal Society at which the Copley Medal was awarded to Charles Darwin in absentia, Lyell announced publicly that he had changed his mind concerning species and declared his faith in Darwin’s theory of the indefinite modification of species by natural selection. Between 1865 and 1868 Lyell rewrote and revised the Principles for the tenth edition, so as to make it conform in every part with Darwin’s theory and to express his wholehearted conviction of the truth of the theory of evolution by natural selection. In the second volume of the tenth edition, published in 1868, Lyell devoted the first ten chapters of book III to various aspects of the species question. In chapter 37 he discussed the theory of natural selection and in four succeeding chapters showed how the complex facts of the geographical distribution of species were explicable in terms of natural selection but not by any other hypothesis. The tenth edition of the Principles was Lyell’s last great feat of scientific writing. The eleventh edition of 1872 and the twelfth edition, published in 1875 after his death, included only minor revisions.

In 1864 Lyell was elected president of the British Association for the Advancement of Science and delivered the presidential address at the annual meeting at Bath. Also in 1864 he was created a baronet by Queen Victoria. Since their marriage in 1832 Lady Lyell had helped her husband with his correspondence, writing many of hts letters from dictation; but in 1865 Lyell engaged as his secretary Arabella Buckley, and his letters after that were usually written in her hand. After 1869 Lyell’s health began to fail. His eyesight became gradually worse, until he was blind, and his strength diminished. Yet he continued to make geological expeditions to various places in the British Isles; and in April 1872 he and Lady Lyell, accompanied by T. McKcnna Hughes, went to the south of France to visit the caves of Aurignac.

On 25 April 1873 Lady Lyell died unexpectedly; and the loss, after forty years of so close and constant a companion, was a severe blow to Lyell. After some months of failing health he died on 22 February 1875 and was buried in Westminster Abbey.

In addition to his knighthood and baronetcy lyell received many honors. The Royal Society awarded him the Copley Medal and the Royal Medal; the Geological Society, the Wollaston Medal. He was elected a member of the American Philosophical Society and a corresponding member of the Institut de France and of the Royal Academy of Sciences at Berlin, in addition to membership in many other scientific and learned societies.

Lyell established geology as a science. He applied to the subject the strictest discipline of rigorous reasoning and expunged it of all that was merely fanciful and speculative. His criteria for admissible causes in geology stand today more strongly than ever; and the kind of detailed analogy which he drew between ancient and modern conditions in oceans, lakes, streams, and estuaries foreshadowed the modern development of paleoecology. In certain theoretical interpretations Lyell was clearly wrong. Until 1857 he defended the view that erratic boulders had been transported by icebergs, whereas for the most part they had been transported by continental glaciation. Lyell also exaggerated the role of the sea in shaping the form of the land and did not fully appreciate the immense scale of subaerial denudation in determining landforms. For many years he mistakenly upheld the fixity of species. Yet Lyell’s theoretical positions, even when wrong, were always carefully reasoned; and he showed an extraordinary capacity even into old age to understand the meaning of new evidence and to change his mind.

After Lyell’s death his reputation, together with that of Darwin, suffered a serious decline—principally because, in the controversy over the age of the earth initiated in ,11865 by Lord Kelvin, Kelvin and other physicists had asserted that the earth could not be older than 10 to 25 million years. Within these time limits geologists could not account for the long series of geological changes which had occurred, in terms of the uniform action of natural causes. Consequently there was a tendency for geologists to revert to catastrophic interpretations of past geological changes. Lord Kelvin’s estimate of the age of the earth was based on calculations of the rate of heat loss by the earth, assuming that it had begun as an incandescent molten mass, approximately at the temperature of the sun, and had gradually cooled according to the laws of radiation. Kelvin had admitted that his calculations would be invalidated if any steady source of heat were to be discovered within the earth.

As early as 1830 Lyell had concluded that the occurrence of volcanic activity throughout all periods of geological history required a steady source of heat within the earth, and he had rejected the concept of a gradually cooling earth. In 1904 Ernest Rutherford pointed out that a steady source of heat within the earth had been found in the discovery of radioactivity. Estimates of the age of the earth were rapidly revised upward and the modern estimates, which are in excess of 4,000 million years, are great enough to allow the uniform action of gradual causes to produce all the geological changes that have occurred, just as they are also adequate to allow the gradual action of natural selection to produce all the results of evolution in biology. Lyell’s faith in geological explanation in terms of the uniform action of observable natural processes has been vindicated by the progress of his science.


1. C. Prévost, “De l’importance de I’étude des corps organisés vivants pour la géologic positive,” inMémoires de la Société d’histoire naturelle de Paris, 1 (1823), 259–268, see 262.

2. “On a Dike of Serpentine, Cutting Through Sandstone, in the County Of Forfar,” inEdinburgh Journal of Science, 3 (1825), 112, 126.

3. “On the Structure of Lavas Which Have Consolidated on Steep Slopes; With Remarks on the Mode of Origin of Mount Etna, and on the Theory of ’Craters of Elevation,’” in Philosophical Transactions of the Royal Society, 148 (1858), 703–786, see 761.

4.The Antiquity of Man, 2nd ed. (London, 1863), p. 393.

5. Darwin to Lyell, 6 Mar. 1863, in The Life and Letters of Charles Darwin(London, 1888), III, 11–13.

6. Lyell to Darwin, 11 Mar. 1863, in Life, Letters and Journals of Sir Charles Lyell Bart. (London, 1881), 11, 363–364.


I. Original Works. There is a fairly complete list of Lyell’s scientific papers in the Royal Society’s Catalogue of Scientific Papers and of all his writings in appendix E to Life, Letters and Journals of Sir Charles Lyell Bart., Katherine M. Lyell, ed., 2 vols. (London, 1881). For Lyell’s publications up to 1841, the bibliography in Leonard G, Wilson, Charles Lyell, the Years to 1841:The Revolution in Geology (New Haven-London, 1972), contains some items omitted from the other two lists and complete references to his early articles in the Quarterly Review.

Selected papers are “On a Recent Formation of Freshwater Limestone in Forfarshire, and on Some Recent Deposits of Freshwater Marl; With a Comparison of Recent With Ancient Freshwater Formations; and an Appendix on the Gyrogonite or Seed Vessel of the Chara” (1824), in Transactions of the Geological Society of London, 2nd ser., 2 (1829), 73–96; “The Bakerian Lecture. On the Proofs of a Gradual Rising of the Land in Certain Parts of Sweden,” in Philosophical Transactions of the Royal Society, 125 (1835), 1–38; “On the Relative Ages of the Tertiary Deposits Commonly Called ‘Crag’ in the Counties of Norfolk and Suffolk,” in Magazine of Natural History, n.s. 3 (1839), 313–330; “On the Upright Fossil Trees Found at Different Levels in the Coal Strata of Cumberland, Nova Scotia” (1843), in Proceedings of the Geological Society of London,4 (1842-1845), 176–178; “On Craters of Denudation, with Observations on the Structure and Growth of Volcanic Cones,” in Quarterly Journal of the Geological Society of London,6 (1850), 207–234; “The Tertiary Strata of Belgium and French Flanders,” ibid.,8 (1852), 277–371; and “On the Structure of Lavas Which Have Consolidated on Steep Slopes; With Remarks on the Mode of Origin of Mount Etna, and on the Theory of ’Craters of Elevation,” M in Philosophical Transactions of the Royal Society,148 (1858), 703–786.

Lyell’s books were Principles of Geology. Being an Attempt to Explain the Former Changes of the Earth’s Surface by Reference to Causes Now in Operation, 3 vols. (London, 1830-1833; 2nd ed., 2 vols., 1832–1833; 3rd 4 vols,, 1834; 4th ed., 1835; 5th ed., 1837; 6th ed., 3 v 1840; 7th ed., 1 vol., 1847; 8th ed., 1850; 9th ed., 1853; 10th ed., 2 vols., 1867–1868; 11th ed., 1872; 12th ed., 1875); Elements of Geology (London, 1838; 2nd ed., 2 vols., 1841; 3rd ed., pub. as A Manual of Elementary Geology 1 vol., 1851; 4th ed., 1852; 5th ed., 1855; 6th ed., 1865); Travels in North America, in the Years 1841–2; With Geological Observations on the United States, Canada and Nova Scotia, 2 vols. (London-New York, 1845); A Second Visit to the United States of North America, 2 vols. (London, 1849); The Geological Evidences of the Antiquity of Man With Remarks on Theories of the Origin of Species by Variation (London, 1863; 2nd ed., 1863; 3rd ed., 1863; 4th ed., 1873); and The Student’s Elements of Geology (London, 1871).

Many of Lyell’s letters and travel diaries were published in the Life, Letters and Journals of Sir Charles Lyell Bart., Katherine M. Lyell, ed., 2 vols. (London, 1881). The original copies of many of Lyell’s letters to members of his family, his scientific journals, and his notebooks are the property of Lord Lyell of Kinnordy, Kirriemuir, Angus, Scotland. Lyell’s letters to other scientists are scattered among libraries and MS collections, both public and private, throughout the world.

Between 1855 and 1861 Lyell filled seven notebooks with notes and references on the species question; these have been published as Sir Charles Lyell’Scientific Journals on the Species Question, Leonard G. Wilson, ed. (New Haven-London, 1972).

II. Secondary Literature. In addition to K. M. Lyell’s Life, Letters and Journals, three brief popular biographies of Lyell have been published: Sir Edward Bailey, Charles Lyell (New York, 1963); Thomas George Bonney, Charles Lyell and Modern Geology (London, 1895); and F, J, North, Sir Charles Lyell (London). Although all of these biographies are heavily dependent on the Life, Letters and Journals and on Lyell’s published writings, each was written by a professional geologist who contributed useful insights into Lyell’s work.

Leonard G. Wilson, Charles Lyell, the Years to 1841: The Revolution in Geology (New Haven-London, 1972), is the first of three volumes of a detailed, large-scale biography of Lyell based on extensive study of both published and MS sources.

There are references to Lyell among the lives and letters of many eminent Victorians, both British and American. Of particular value are Katherine M. Lyell, ed., Memoir of Leonard Horner, F.R.S., F.G.S., Consisting of Letters to His Family and From Some of His Friends, 2 vols. (London, 1890); and Frances Joanna Bunbury, ed., Life, Letters and Journals of Sir Charles J. F. Bunbury Bart., 2 vols. (London, 1894).

The intellectual and scientific background to Lyell’s thought is discussed in a lively study by Charles Coulston Gillispie, Genesis and Geology (Cambridge, Mass., 1951). Various aspects of Lyell’s concept of uniformity are discussed in the following: Walter F. Cannon, “The Uniformitarian-Catastrophist Debate,” in Isis,51 (I960), 38–55; and “The Impact of Uniformitarianism. Two Letters From John Herschel to Charles Lyell 1836–1837,” in Proceedings of the American Philosophical Society,105 (1961), 301–314; R. Hooykaas, Natural Law and Divine Miracle, A Historical-Critical Study of the Principle of Uniformity in Geology, Biology and Theology (Leiden, 1959), an attack on the principle of uniformity, inspired by religious doctrines; M, J, S. Rudwick, “A Critique of Uniformitarian Geology: A Letter From W. D. Conybeare to Charles Lyell, 1841,” in Proceedings of the American Philosophical Society,111 (1967), 272–287; and “Lyell on Etna, and the Antiquity of the Earth,” in Cecil J. Schneer, ed., Toward a History of Geology (Cambridge, Mass., 1969), pp. 288–304; and Leonard G. Wilson, “The Development of the Concept of Uniformitarianism in the Mind of Charles Lyell,” in Proceedings of the Tenth International Congress of the History of Science (Paris, 1964), pp. 993–996; and “The Origins of Charles Lyell’s Uniformitarianism,” in Uniformity and Simplicity (New York, 1967), pp. 35–62.

Leonard G. Wilson

Lyell, Charles

views updated May 18 2018


LYELL, CHARLES (1797–1875), Scottish geologist and man of letters.

Charles Lyell was brought up and educated in the south of England, ultimately graduating in classics from Exeter College, Oxford, in 1819. He then entered Lincoln's Inn, and became a barrister in 1822, but by then much of his time was taken up by science. The son of a wealthy botanist, Lyell had early been fascinated by natural history, and like many other young gentlemen at Oxford he had been spellbound by the geological lectures of the charismatic William Buckland (1784–1856).

Buckland was an important figure in the genteel Geological Society of London, founded in 1807 with the aim of reinventing geology as an empirical discipline focused on the strata. Such geologists rejected what they saw as the unbridled speculations of eighteenth-century "theories of the earth," and they shared Lyell's determination to "free the science from Moses" (the putative author of the Book of Genesis). By the 1820s many geologists agreed that the earth had supported life long before the creation of man. Buckland himself promoted a progressive vision of earth history, and his sensational research on cave fossils vividly demonstrated the value of present-day evidence (such as bones chewed by Buckland's pet hyena Billy) in picturing the remote past. For Lyell this approach soon hardened into a fundamental principle: processes observed in the present world were, he claimed, sufficient to account for all existing traces of the past.

In 1825 Lyell's first scientific paper was published, based on geological fieldwork undertaken near his family seat in Scotland. By now he was moving in the uppermost scientific circles in London and Paris, becoming secretary of the Geological Society of London in 1823 and a fellow of the Royal Society in 1826. The modest income from his sporadic legal work was soon supplemented by literary activity: in 1825 the Tory publisher John Murray invited him to write for the prestigious Quarterly Review. A moderate Whig and theologically liberal, Lyell used this platform to promote reform among the Tory intelligentsia, protesting against the clerical domination of English intellectual life and (encouraged by clerical geologists like Buckland) contesting the Bible's authority over scientific matters. However, Lyell was so concerned to distance himself from the rising tide of evolutionary speculation that he even denied any directional element to the history of life on Earth, viewing the world instead as a self-sustaining system shaped by uniformly acting natural processes. Here he took his cue from older Scottish Enlightenment models, and from contemporary research on the Continent. Massive cataclysms—such as the "geological deluge" proposed by Buckland and others to explain what we call glacial phenomena—had no place in this vision of stability and regeneration, which Lyell set out with a wealth of empirical evidence (most of it gathered from the work of others) in his literary masterpiece, Principles of Geology (1830–1833).

This book is sometimes credited with having introduced into British earth science such concepts as the great antiquity of the earth, though this idea had long been a tacit commonplace among geologists. Lyell's greatest achievements did not lie in matters of geological theory: his most cherished claims never caught on, such as his denial of progression in the history of life on Earth and his insistence that no past cataclysm could have been greater than present-day equivalents. His true importance lay in his ability to synthesize and deploy vast quantities of abstruse scientific data within an elegant, rhetorically compelling work of literature. Aimed at a dual readership of specialists and nonspecialists, the Principles transformed the public profile of geology and its genteel practitioners at a critical stage in the science's development. As a confident statement of geology's authority as a secular discipline, blazoning its independence from biblical scholarship, the Principles played a major role both in ongoing boundary disputes between science and theology, and in wider debates about man's place in nature. In such matters, the pen proved mightier than the geological hammer.

The Principles sold well and was widely read: among its more celebrated admirers was the young Charles Darwin. New and cheaper editions (often substantially revised) followed, as did translations into French and German. The sometime barrister had found his vocation as a scientific author and advocate for science; he also served briefly as professor of geology at King's College, London (1831–1833), and was much in demand as a visiting lecturer both in Britain and in the United States. Lyell was knighted in 1848 and became a baronet in 1864; his wife, Mary (née Horner), whom he had married in 1832, was now a prominent hostess in London intellectual society. Lyell's later publications included Elements of Geology (1838), two sets of Travels in North America (1845 and 1849), and The Antiquity of Man (1863), in which he summarized the recently unearthed evidence for the coexistence of fossil humans with extinct mammals. In the tenth edition of the Principles (1867–1868) Lyell at last gave his qualified and reluctant approval to Darwin's theory of evolution. Mary died in 1873, and Lyell survived her by less than two years. He is buried in Westminster Abbey.

See alsoCuvier, Georges; Darwin, Charles; Evolution; Science and Technology.


Primary Sources

Lyell, Charles. Principles of Geology. Introduced by Martin J. S. Rudwick. 3 vols. Chicago, Illinois, 1990–1991. Facsimile reprint of 1st edition (1830–1833) with excellent introduction.

——. Principles of Geology. Edited and introduced by James A. Secord. London, 1997. Convenient onevolume abridged edition with a superb introductory essay on Lyell and his cultural context.

Secondary Sources

Rudwick, Martin J. S. "The Strategy of Lyell's Principles of Geology." Isis 61 (1970): 5–33. Ground-breaking analysis of the rhetorical structure of the Principles.

Wilson, Leonard G. Charles Lyell: The Years to 1841: The Revolution in Geology. New Haven, Conn., 1972. The first part of a still-uncompleted biography: an essential (if somewhat adulatory) reference-point for Lyell's early career.

——. Lyell in America: Transatlantic Geology, 1841–1853. Baltimore, Md., 1998. The second part of the biography, covering Lyell's years as an international celebrity.

Ralph O'Connor

Sir Charles Lyell

views updated May 21 2018

Sir Charles Lyell

The Scottish geologist Sir Charles Lyell (1797-1875) established the uniformitarian view of geology.

Charles Lyell, the eldest son of Charles Lyell, was born at Kinnordy, Forfar, the family estate, on Nov. 14, 1797. During his early childhood, the family moved to Lyndhurst, Hampshire, where he received his early education. He showed a keen interest in collecting moths, a hobby he pursued throughout his life. At age 15 Lyell read Robert Bakewell's Introduction to Geology (1813), which aroused his interest in geology. Entering Exeter College, Oxford, in 1816, he studied classics and attended geology lectures with William Buckland.

Lyell earned his bachelor's degree in 1819 and then entered Lincoln's Inn to study law. However, eye trouble interrupted his law study, and he developed an even greater affinity for geological study. He joined the Geological Society, becoming its secretary in 1823 and later president for two terms.

Beginning with Rome in 1820, Lyell made several geological tours on the Continent as well as in England and Scotland. Returning to law in 1825, he was called to the bar and practiced intermittently for 3 years, during which time he also wrote many papers on geological subjects, published primarily in the proceedings of the Geological Society.

In Principles of Geology (3 vols., 1830-1833) Lyell attempted to explain the former changes of the earth's surface by reference to causes now in operation. The continuous revision and expansion of the Principles, his main object in life, form a record of 40 years' progress in geology through the 12 editions. The twelfth edition was published posthumously in 1875. In these volumes, through his wide-ranging synthesis of geological phenomena observed in Europe and America, Lyell established the uniformitarian view of geology; that is, contemporary processes, long continued, of land erosion and deposition coupled with slow uplift of sea floors were a sound basis for reconstructing the earth's past. The wasting land of one age becomes the rocks of later ages. This view, set out with forensic skill, opposed and displaced the catastrophist view of sudden violent occurrences, the last of which was believed to be Noah's flood.

Lyell served as the first professor of geology at King's College, London, from 1831 to 1833. In 1832 he married Mary Horner; they had no children. He stopped teaching to devote his time to research and writing. In addition to the Principles, he wrote Manual of Elementary Geology (1838), two accounts of his North American travels (1845, 1849), and Geological Evidence of the Antiquity of Man (3 eds., 1863-1873).

Lyell was elected a fellow of the Royal Society in 1826; was knighted in 1848; was awarded the Copley Medal in 1858; and was created baronet in 1864. He died on Feb. 22, 1875, in London and was buried in Westminster Abbey.

Further Reading

Important biographical material is in Life, Letters and Journals of Sir Charles Lyell, Bart, edited by his sister-in-law, Katherine Lyell (2 vols., 1881). The two major studies of Lyell are Thomas G. Bonney, Charles Lyell and Modern Geology (1901), and Edward Bailey, Charles Lyell (1962). □

Lyell, Charles

views updated May 08 2018

Lyell, Charles (1797–1875) Author of the influential Principles of Geology, 12 editions of which were published between 1830 and 1875. He was an extreme uniformitarian, emphasizing a great age for the Earth. He thus influenced Darwin by allowing the time needed for evolutionary changes to occur. See UNIFORMITARIANISM; and DRIFT.

Lyell, Sir Charles

views updated May 18 2018

Lyell, Sir Charles (1797–1875) Scottish geologist. He was influential in shaping 19th-century ideas about science and wrote the popular three-volume Principles of Geology (1830–33). Other works include Elements of Geology (1838) and The Geological Evidence of the Antiquity of Man (1863).

About this article

Sir Charles Lyell

All Sources -
Updated Aug 13 2018 About content Print Topic