At the end of 1831 a young Cambridge graduate and budding priest set sail on The Beagle on a five year trip round the world. He was to be the naturalist-cum-companion to the captain – Robert Fitzroy. He got the offer because he was one of the most able young naturalists of his generation. He received the letter from Rev John Henslow suggesting he should go when he returned to Shrewsbury after a three trip around North Wales. Most of that he was carrying out field geology and from the 3rd to the 20th August he was under the tutelage of Rev Adam Sedgwick, the Woodwardian Professor of geology at Cambridge. Sedgwick had gone to Wales to work out the stratigraphy and structure of North Wales, and “picked up” Darwin in Shrewsbury, as he knew Darwin as a student. After Darwin left Sedgwick on 20th August, Sedgwick began to sort out what he termed the Cambrian. He returned to Cambridge at the end of October with much work still to do and he returned to Wales frequently over the next dozen years. This map shows their routes
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And this blog referring to a paper of mine Just before the Beagle gives more detail.
(Spoiler; a longer study is about to be published!)
Darwin’s main interest on the voyage was the geology, which he wrote up in several books. On the voyage Darwin read Lyell’s Principles of Geology and after his return he looked more to Lyell than other geologists. However the influence of Sedgwick, and probably Henslow, was of far more significance and here I seek to present that the importance of Sedgwick to this novice geologist is more important than that of Charles Lyell.
Three mentors; Sedgwick, Henslow and Lyell
Sedgwick hardly needed to take Darwin on the trip and his notes make no mention of him. Here I consider first the relationship of Darwin with the peppery older geologist, which also brings out some of the relationships, perceived or not, of the rising science of geology and Christian belief. And, most importantly, I consider what geology Darwin learnt from Sedgwick and how this moulded the geology of the Beagle.
THE SIGNIFICANCE TO SEDGWICK
It is difficult to discern any tangible benefit to Sedgwick in taking along Darwin as a companion, beyond that of training up another student as a geologist and simply to have company on a long journey. This is, of course, what Henslow had done for Darwin while he was at Cambridge. Some of the pride Sedgwick felt for his young pupil can be seen both in the fact that it was Sedgwick rather than Henslow who read out Darwin’s letters to Henslow on the geology of South America on 16 November 1835 (Barrett, 1977:16-19) and wrote a “bonne bouche” to Dr Butler of Shrewsbury School. Dr Butler sent an extract of this letter to Robert Darwin which Susan Darwin copied out in a letter to Charles, “He is doing admirably in S. America, & has already sent home a Collection above all praise. – There was some risk of him turning out an idle man: but his character will now be fixed, & if God spare his life, he will have a great name among the Naturalists of Europe.” Dr Butler had clearly changed his mind since he regarded the schoolboy Charles as “poco curante”, according to his Autobiography (Darwin & Huxley, 1983:24) for wasting his time over such useless subjects as chemistry. Darwin’s sharp remark in his Autobiography may be due to the bitterness caused by his controversy with Butler’s grandson. It is difficult not to see that Sedgwick was congratulating himself, with very good reason, on tutoring Darwin so well in geology.
Charles and myself outside his old school
DARWIN’S PERSONAL RELATIONSHIP WITH SEDGWICK.
It is tempting to consider the relationship of Darwin and Sedgwick during this tour in the light of their disagreement over evolution 28 years later, rather than focus on their relationship in 1831, when Sedgwick was a highly proficient clerical-geologist and Darwin a scientifically-inclined putative clergyman. Barrett presents Sedgwick as a crotchety, dogmatic bigoted fundamentalist. Crotchety yes, bigot no! In this he seems to be confined by an extreme either/or outlook categorising scientists into either open-minded agnostic evolutionists or narrow-minded religious creationists, reminiscent of Clarence Darrow and his depiction of Jennings Bryan and his other antagonists at the Scopes trial. That depiction of the Scopes Trial has worn somewhat thin as Numbers (1998) and Larson (1997) have made abundantly clear. As Clark and Hughes stress the Moderate Evangelicalism of Sedgwick, he is not an obvious candidate for the latter. Frank Turner (1978) in his seminal article on the professionalisation of science refers rather patronisingly to the “by no means inglorious role” of clergyman-scientists like Sedgwick, Henslow, Whewell and Ray. However matters became worse when he incorrectly identified the clerical-scientists mentioned in Hooker’s letter to Harvey in June 1860, written in response to a letter from Harvey who put forward scientific and theological objections to Darwin. Hooker referred to the ordained scientists Haughton, Miller and Sedgwick “as asses between bundles of hay” because they rejected Darwin’s theories, which is wonderful from the son-in-law of two clergy-naturalists. Turner failed to note that Hooker was writing to Harvey, professor of Botany at Trinity College, Dublin, about his colleague Haughton, geology professor at Dublin, and Rev William Miller, professor of mineralogy at Cambridge, whom Turner confused with Hugh Miller who had died five years previously. As an aside in 1871 Haughton estimated that the base of the Cambrian was 1526 m.y., three times present estimates and in accord with Darwin’s estimates for the Wealden, and considerably longer than Huxley’s estimates of about 100 million. Ironically Harvey wrote a long and friendly letter to Darwin on 24 August 1860 explaining why he could not accept Natural Selection. Almost as much an ass “between bundles of hay” as this trio was John Henslow, Hooker’s father-in-law, who kept his colours firmly nailed to the fence. I ought to say, proudly, that I, too, am an ass!
Both Barrett and Turner presuppose that Christian belief prevents sound scientific work, as Turner claimed without evidence “Certain questions, areas of inquiry ….were discouraged because they carried the implications of impiety, immorality or blasphemy.” These were not identified. If there were proscribed “areas of inquiry” then these did not include any branch of geology, or even studies on the non-fixity of species or else Dean W. Herbert of Manchester would have been charged with blasphemy or heresy long before being made Dean in 1840! In fact, the only Dean or Bishop would have been Dean Cockburn of York who wrote so much drivel trying to disprove geology and lambasting clerical geologists like Buckland and Sedgwick. Behind the assertions of Barrett and Turner is an uncritical acceptance of the conflict thesis which assumes rather than demonstrates antagonism between science and religion and thus between clerical scientists and those styled by Moore as “Young Reformers”. In their Gifford Lectures Reconstructing Nature, Brooke and Cantor deal critically with these issues. Their assessment of Desmond’s Huxley is relevant here and their comment is most apt, “However, partisan history from whichever camp tends to downplay or distort opposing positions. Thus although Desmond’s book has many strengths, appreciation of Huxley’s critics – such as … Wilberforce or … Mivart – is not one of them”. (Brooke & Cantor 1998:68) As Desmond wrongly claimed that Owen “was coaxing Sam beyond the Six Days to a more informed opposition” (Desmond, p281)- hardly likely for one who attended Buckland’s lectures for three years running and who crowned Murchison “King of Siluria” -, so Barrett wrongly described Sedgwick as “a religious fundamentalist” (1974, p146) and consistently portrayed him as opinionated and even pontifical, right down to suggestions that Sedgwick forced Darwin to misspell “Llan” as “Slan” which cannot be borne out by either Darwin’s or Sedgwick’s manuscript notes or maps for 1831 and other years. That was because Darwin wrote “L” rather flamboyantly in his maps and notes. Both scholars seem to look for conflict way beyond the evidence. To regard Sedgwick as a fundamentalist is to posit that both Sedgwick’s and Darwin’s geology at this time was essentially Scripturally based with either literal or semi-literal notions of a biblical flood and a limited life span for the earth. This is, of course, the classic presentation of Darwin’s pre-Lyellian and pre-Beagle geology and has been given expression by both Barrett and Gruber (see also Barrett and Gruber Darwin on Man 1974) and a host of other writers. Gruber claimed that Darwin still accepted an Ussher chronology when he boarded the Beagle. During the voyage, due to reading Lyell, “.. he expanded his conception of the time scale on which the history of the earth has unfolded from the Biblical base of 6,000 years to some indefinite number much greater than 20,000 years.” (Gruber, 1974, p101) No evidence was given for this and though conservative theologically neither Henslow nor Sedgwick were remotely literalist. (Clark and Hughes, 1896,passim). Darwin recognised this and said to Rodwell, “What a capital hand is Sedgwick for drawing large cheques upon the Bank of Time!”
Sedgwick was never a literalist as he made clear to Francis Close in 1858, when he wrote, “Don’t think me a bad man, if I tell you that when puzzling my brain (during long by gone years) about this chapter, I have sometimes fancied, that the 3rd + 4th days, had by some mistake of translation been made to change place – formerly I tried all sorts of hypotheses to little satisfaction, so of late years I have little troubled my head with hypotheses, not doubting that in the end, all, all difficulties would vanish”. In his Presidential Address to the Geological Society of 1830 Sedgwick had rejected the identification of “diluvium” with the Biblical Flood. In this Sedgwick was no liberal, but shared the open outlook to geology of many moderate evangelicals. In 1831 Sedgwick probably adopted a variant of the standard “Chaos-Restitution” interpretation of Genesis, which allowed for vast geological ages within an almost literalist rendering of Genesis. Sedgwick’s fights with creationjists are discussed here; Geological Society, London, Special Publications 2009; v. 310; p. 155-170,Michael B. Roberts,Adam Sedgwick (17851873): geologist and evangelical).
Darwin was undoubtedly familiar with this both from his theological reading at Cambridge, from geological writers such as Conybeare and Phillips (1822: ) and from his own grandfather’s writings, which echoed the dominant understanding of Genesis even though “he disbelieved in any revelation”. (Darwin, 1989, vol29 p45). Thus we find in The Botanic Garden the following lines,
Let there be light!” proclaimed the Almighty Lord.
Astonished Chaos heard the potent word; –
Through all his realms the kindling Ether runs,
And the mass starts into a million suns;
From this it is clear Darwin was never a literalist, whether while at Cambridge or before, and his claims in his Autobiography that “I did not then in the least doubt the strict and literal truth of every word in the Bible” must be seen as tricks of memory in later life. In this Darwin simply echoed the current orthodoxy of his day, from which only a noisy minority of Anti-geologists dissented.
Though Darwin’s later lack of faith, or agnosticism, is well-known and it is likely that he rejected Christianity sometime after his return from the Beagle, in 1831 he was more orthodox as a Christian than at any other time. He had just completed his course at Cambridge and was intending to be ordained and although he gave no indication of being an evangelical he was steeped in mainstream Anglican theology. Thus he was hardly likely to differ from Sedgwick on religious grounds as he did later.
As we have seen, the relationship between Sedgwick and Darwin has more often been asserted rather than analysed. Friction, with a theological root, has been assumed rather than demonstrated. To consider the relationship in reverse historical sequence, we begin with his comments on Sedgwick in his Autobiography. Here Darwin wrote respectfully and appreciatively of Sedgwick’s tutoring in 1831, in typically Darwinian understatement, -“This tour was of decided use in teaching me a little how to make out the geology of a country.” Shortly before Sedgwick died Darwin wrote “I am pleased that you remember my attending you in my excursions of 1831. To me, it…made me appreciate the noble science of geology.” This reflects the letter he wrote to Henslow on 18 May 1832 “Tell Prof: Sedgwick he does not know how much I am indebted to him for the Welch expedition. – it has given me an interest in geology” and some to his sisters while travelling on the Beagle. The welcome Sedgwick was given at the Mount during the 1830s is a sure indication of the affection the Darwins’ had for Sedgwick. This affection went a bit further with Susan and Caroline wrote to Darwin on 25 July 1832 that Susan would soon be Mrs Sedgwick! From this one can only conclude that Darwin and Sedgwick got on well on their tour. It was clearly a master-pupil relationship, determined both by the great age difference. For this Darwin must be envied. All was not always sweetness and light as the incident of the waiter at Conway, whom Sedgwick suspected of not giving a sixpenny tip. In fact, this is the only adverse statement about the relationship of Darwin and Sedgwick during their 1831 trip, and it does not concern animosity between the pair but animosity directed at the unfortunate waiter. If Darwin was right in his later years that he had given Sedgwick a mild rebuke this is surely normal human relationships and is typical of what occurs between two or more people who spend sometime together.
Further it is easy to read a breakdown of relationships into their correspondence over Origin of Species in 1859. Sedgwick’s response to Darwin is very critical of his book both on scientific and religious grounds, but Sedgwick did sign himself off as “a son of a monkey”. That self-depreciating humour shows that though Sedgwick could not countenance evolution, he was able to retain his affection for his old pupil. This is apparent in their later exchange of letters in 1868 when George Darwin was offered a Cambridge fellowship.
However it is interesting to consider Darwin’s subsequent relationship with Sedgwick in comparison to Henslow and Lyell. Though Darwin had considerable respect for Sedgwick, he had very little contact with him after returning from the Beagle voyage, whereas he retained considerable affection for Henslow and wrote what can only be termed a eulogy after his death. This may be partly explained by the greater contact and thus more influence Henslow had with Darwin, as opposed to Sedgwick, whose main contact was during this field trip. After his return in 1836 Darwin gravitated to Lyell as a geological mentor rather than Sedgwick. There may well be religious as well as personal and scientific reasons. Although formally “orthodox” while at Cambridge, Darwin never had what may be called any Evangelical fervour, nor was he ever a literalist, despite comments in his Autobiography. It is reasonable to date his “perversion” from orthodox Christianity during Autumn 1838 as he wrote in his diary, “All September … thought much on religion” “ His Autobiography points to the years “1836 to 1839” (Darwin & Huxley, 1983:49).
Of these three mentors Sedgwick was the most Evangelical as both Clark and Hughes, and Marston (1984) make clear. It also becomes apparent in Sedgwick calling with 500 other evangelical clergy for a revision of the Prayer Book in an evangelical direction, and his friendship with Dean Close, whom Sedgwick upbraids for departing from scripture by adopting Miller’s interpretation of Genesis. He would not have been an easy person to see after his return from the Beagle when Darwin was rejecting his calling to the ministry. For one rejecting his initial calling it was best not to see an Evangelical who was about to be invited to become Bishop of Norwich.
Henslow, though orthodox, was less threatening than Sedgwick, but it is easy to see why Darwin gravitated to Lyell rather than his earlier mentors. Not only was Lyell in London much of the time, he was far more liberal theologically with leanings towards Unitarianism and the extreme of the Broad church. Lyell’s affable tolerance was no threat to the perverting Darwin. Lyell’s jovial anti-clericalism would also have made the rejection of an earlier calling easier.
Were it not for the historical singularity that Sedgwick passed through Shrewsbury en route to North Wales, Darwin would not have had more than a passing acquaintance with Sedgwick, probably only as a colleague of Henslow. As they spent eighteen days together in intimate company just before Darwin joined the Beagle there is the temptation to overanalyse the relationship and there are just enough ingredients for a conflict scenario to tilt the relationship into one of personal and religious antagonism. But this is done retrospectively from Sedgwick’s opposition to the Origin of Species in 1860. There is insufficient evidence to suggest whether or not they were close friends, but Darwin retained respect, affection and gratitude to Sedgwick throughout his life. And it was mutual.
DARWIN AS SEDGWICK’S DISCIPLE.
As the field trip was one in which Darwin as a novice geologist was accompanying Sedgwick an experienced and leading geologist, it would be unreasonable to expect that Darwin himself made any profound geological discoveries. The position was, as far as Darwin was concerned, entirely that of pupil and tutor. As both made notes, a comparison of their respective notes, shows how Darwin developed over these weeks.
By the time Sedgwick arrived in Shrewsbury on 2 August Darwin had a moderate grasp of geology and knew the rudiments of mapping, rock identification and the use of a clinometer to measure dip and strike (Roberts, 1996, 2000). Darwin’s geological understanding was not simply what he had learnt in the last few weeks, but was also what he had picked up in a slightly haphazard way during the previous ten years. From his reference to Cotton and the Bellstone in his Autobiography (Darwin & Huxley, 1983:28), he was familiar with some rudiments of geology by the time he was a teenager. He probably dabbled before going to Edinburgh and there learnt some geology from Jameson and Hope, who were two of the most experienced teachers of geology. As Secord emphasises so strongly by the time Darwin left Edinburgh he had a good all-round knowledge of the subject and was familiar with the geological column from the Old Red Sandstone to the Tertiary. Despite Darwin claiming in his Autobiography that he did not attend Sedgwick’s geology lectures at Cambridge, contemporaries claimed he did. Thus it is would be wrong to presume that Darwin knew no geology before 1831. From his environment both in Shrewsbury and at the universities, he would have acquired general notions of vast ages, strata, geological ages and fossils, as would any person who was competent in natural history at that time. His father’s circle included men familiar with geology and Dr Robert Darwin’s colleague, Dr Dugard, was a member of the Geological Society and thus Darwin would have had access to publications of the Geological Society and other geological works. It would be remarkable if he was not familiar with the work of Arthur Aiken on Shropshire and North Wales and probably that of Robert Townson too (Torrens, 1984). His mentor in entymology, the Rev F.W.Hope, was well-informed in geology and had his own copy of Fleming’s response to Buckland. This evidence is circumstantial, but it would be surprising if the budding naturalist, who carried out many chemical experiments in the garden laboratory, was not also familiar with the rudiments of geology. However it is fair to state that Darwin was in need of competent tuition in field geology. Apart from that, as Secord wrote, “Darwin was one of the best-trained men of his age in Great Britain.” He had, of course, spent some considerable time in the field on his own but his notes and maps indicate that he was floundering. He had tried to make maps (Roberts 2000) and visited Llanymynech (Roberts, 1996) and had most probably visited the area round the Stiperstones and the Bog to the south-west of Shrewsbury. Before Sedgwick arrived he had probably spent at least six or seven days in the field, and had spent considerable time at home, both making his maps, playing with his clinometer and probably reading up on geology.
During their ten days together Sedgwick introduced Darwin to a very wide range of rock types and a fascinating range of geology. There was the additional frisson of working with someone who was on the pioneering and cutting-edge of geology. Into today’s terms Darwin had to consider strata from the Late Precambrian to the Triassic, though, of course, the elucidation of the Lower Palaeozoic was in its infancy. In descending stratigraphic order they looked at the drift at Valle Crucis and the Cefn caves, New Red Sandstone in the Vale of Clwyd; Carboniferous Limestone above Llangollen, the vale of Clwyd, the North Wales coast and Angelsea; allegedly, and putative Old Red Sandstone in the Vale of Clwyd and Anglesey, and the real mckoy in Anglesey; various slates and volcanics of the Lower Palaeozoic between Llangollen and Ruthin and in Snowdonia; trap dikes in Anglesey; and finally various facies of the then unknown Mona Complex in Angelsea. Apart from the Carboniferous the “status” of all these were controversial or were at the cutting edge of geology.
Sedgwick also taught Darwin to observe and describe the lithology of these strata and thus he was familiarised with greywackes, slates of all kinds, conglomerates and sandstones and limestones as well as a wide variety of igneous and metamorphic rocks. His knowledge of mineralogy increased greatly during the trip and he became adept at recognising a wide variety of minerals, although he long had had an interest in minerals. His increasing skill in mineralogy is shown by the absence of minerals recorded at both Llanymynech and the early stages of the tour, and after leaving Conwy he recorded a variety of minerals. His mineralogy was even more detailed after leaving Sedgwick on the final leg from Cwm Idwal to Barmouth.
As well as lithology and mineralogy Sedgwick also introduced Darwin to aspects of structural geology and how to measure dip and strike of both bedding and cleavage. Both Darwin’s and Sedgwick’s notes contain many references to cleavage and on some “Greywacke” above Penmaenmawr Darwin commented “The coloured seams in the rock P. Sedgwick remarks generally indicate the strata”. Sedgwick included his findings about cleavage in his article of 1835 (Sedgwick 1835), Darwin recorded many examples of cleavage on his voyage especially on the Falkland Islands and in a chapter on South America. Darwin’s Geology of South America emphasised the difference of stratification and cleavage resulting in a response from Joseph Hooker on the Tibet border in 1849,
Stratification is vexation,
Foliation’s twice as bad;
Where joints there be,
They puzzle me;
And cleavage drives me mad.
However it took 20 years to convince all geologists that cleavage was different to bedding and one of the last to accept cleavage was Lyell, despite strong letters from Darwin culminating with, “you are wrong & a heretic on this point I know well.”—
If my argument that Darwin also visited Anglesey is correct, then he was introduced to a yet wider sphere of geology, which turned out to be vital on the Beagle voyage. Though the geology of Anglesey rocks were of little use to Sedgwick in preparation for Snowdonia, they were of great use to Darwin for the rest of the world. The manifold dikes they investigated showed Darwin the variation in similar igneous rocks and were good preparation for the volcanic islands. The metamorphic strata of the future Mona complex gave an insight into both granitic and gneissic terrains and of schists and altered, even parboiled, greywacke, along with the distinction of altered and unaltered conglomerates and breccias, or rather metamorphosed and unmetamorphosed. Using the brief comments in the Red Notebook as signposts, the influence of both Henslow and Sedgwick on Anglesey on his geology of South America becomes manifest.
One of the ironies of popular accounts of the 1831 field trip is the assertion that Darwin and Sedgwick went on a walking holiday combined with a fossil-hunting trip. Nothing could be further from the truth, but old myths die hard and are still being published in Shrewsbury in the Third Millennium. By and large fossils were incidental to their work and the notes of both geologists make few references to fossils. However Sedgwick himself recorded the presence or absence of fossils at many localities and on several occasions when Darwin and Sedgwick visited localities together only Darwin recorded fossils, presumably having been guided to look for them. While travelling on his own Darwin recorded fossils at Cwm Idwal and on Moel Siabod and clearly understood the various types of fossils, sufficiently so to identify them on the Beagle Voyage as he did in the Falkland Islands.
Darwin was not taken to a classic area and shown the long-understood geology by an experienced teacher, as happens to most novice geologists. Instead he was taken to a relatively unknown area by an experienced geologist, who first wished to check out the previous work of Greenough in the Vale of Clwyd, secondly to work out the mass of strata in Snowdonia which were loosely known as Killas, or lumped together as Greywacke, with associated igneous rocks, and thirdly to the complex terrain of Anglesey. This resulted in a very different learning experience and would satisfy some modern theories of teaching, as the approach was one of discovery rather than being taught “eternal verities”. He was not only taught to observe but to think as well.
In the Vale of Clwyd Darwin was introduced to Sedgwick’s doubts about the existence of Old Red Sandstone marked on Greenough’s map, and then was sent on a traverse to test whether or not it was present. Much of the time Darwin was shadowing Sedgwick and receiving direct tuition, indicated by a frequent near verbal agreement in the two sets of notes.
In conclusion, the field trip with Sedgwick had far more influence than the reading of Lyell’s Principles of Geology in Darwin’s developing geological skills. Lyell gave Darwin a theoretical and conceptual framework, which is very evident when one compares The Principles of Geology with the three volumes of the Geology of the Beagle. Sedgwick gave Darwin something more important by teaching him the skills of practical geological observation in the field and rigourous geological note taking. But a comparison of Geological Observations of South America and his paper on the Falklands indicate that the influence of this trip went far beyond the mere teaching of geological skills.
This is evidenced first by both the content and the style of Darwin’s notes, and how they evolved from his first notes at Llanymynech and, for our purposes, culminating with those made at Quail Island. (Roberts, 1996). The development of Darwin’s skill can be seen graphically by simply reading through his notes in sequence from those taken at Llanymynech, then during his Welsh field trip and finally the first few days of notes taken on Quail Island, which were his first field days on the Beagle voyage. The notes taken at Llanymynech are simply indifferent and are little more than his first use of a clinometer. Though he sought to describe and interpret the geology he observed, he notes have all the hallmarks of a not very competent beginner. The notes which Darwin made in Cwm Idwal and on Quail Island both show the influence of Sedgwick.
It is evidenced secondly by the way Darwin used and developed both Henslow’s Anglesey Memoir and Sedgwick’s interpretation of it. Darwin’s notes on Anglesey may be missing, but the threads of thought can be traced through his notebooks into his published work.
Darwin’s comment; “This tour was of decided use in teaching me a little how to make out the geology of a country” (Darwin &Huxley,1983:39) is a masterly understatement of his debt to Sedgwick. He should have said “continent “ or “the world” instead of country. Were it not for Sedgwick’s tutoring the reading of Lyell would have been of limited value. Sedgwick taught Darwin the practical geological skills and a sound basis of geology, whereas Lyell gave Darwin a daring conceptual and theoretical framework. Without the practical skills learnt from Sedgwick during these few days his three volumes on the geology of the Beagle voyage Darwin would have “started up a machinery as wild .. as Bishop Wilkin’s locomotive that was to sail with us to the moon.”
His birit to St Paul’s Rocks in the middle of the Atlantic show how much geology he had learnt as on 16th February 1832 Darwin visited St Paul’s Rocks and identified serpentine, which required great geological insight;
“The rocks are serpentine. & in the lower parts mixed with much Diallage.”
and then commented;
“Is not this the first Island in the Atlantic which has been shown not to be of Volcanic origin?”
 : Darwin, C. R. 2.1832. Geological diary: St Pauls. CUL-DAR32.37-38.
The Darwin manuscripts (DAR) are quoted with permission of the Syndics of Cambridge University Library. The Sedgwick Notebooks and Maps are cited or reproduced with permission of xxxx of the Sedgwick Museum Cambridge, and the letter of Sedgwick to Close by permission of Dean Close School, Cheltenham.
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