the removal of the library and catalogues to the Bodleian destroys the incentive to study and add to the collection because of the absence of readily accessible reference works . divorced from the specimens the catalogues become neglected , and ultimately the specimens are thrown away because the catalogues are not to hand . so are lost all Dr Plot &apos;s figured specimens and the great collection of Edward Lhwyd , his assistant . it is very interesting to see the composition of a seventeenth-century palaeontologist &apos;s reference library . Plot , in addition to Biblical quotations and philosophical transaction references , alludes to no less than fifty-two works . amongst these the elder Pliny &apos;s writings are prominent . his classification of fossils is essentially that of Gesner erected 111 years before . when I say that the four main groups in this classification are stones relating to heavenly bodies ; those relating to the inferior heavens ; those relating to the atmosphere ; and those relating to the watery kingdoms , you will gather that it does not rest on any sound scientific footing . Dr Plot himself has no tremendous regard for this method ; but he says it is better than classifying the things alphabetically . I beg leave to doubt this . then there comes out of Yorkshire the learned Dr Martin Lister with an opinion on fossils , which , emanating as it does from the foremost conchologist of the day , can hardly be ignored . Lister has figured recent and fossil shells , side by side , not , as might be imagined , to show their essential similarity but as an illustration of the plagiarism of nature . Lister &apos;s theory might well be christened ( acknowledging our indebtedness to Siegfried Sassoon ) the pseudomorphic hieroglyphic hypothesis , since whilst denying the former vitality of fossils he suggests that different types of self-generated shell-like stones might characterize different rocks . it might therefore be said that his lapse in regarding fossils as sports of nature is here offset by his penetration as to their possible use . it would certainly be possible to use a tool of which the true nature was unknown , if , empirically , it had been found to serve a useful purpose . but to credit Lister with the first formulation of the basic principle of stratigraphy , as has been claimed , would be to bestow credit falsely . I think Lister had in mind merely the characterizing of different types of rocks by distinctive fossils . today this would be called recognizing the facies of the rocks and Lister &apos;s ingenious proposal , as it was entitled , to make a map showing the surface distribution of strata was a proposal for a mineral , not a true geological map . such a map would , for instance , colour all limestone outcrops under the same shade . although of value in mining and quarrying operations it is academically barren . it can make no contribution to working out earth-history . the primary division of strata in the hierarchy of their classification is according to age not lithology . to elevate the latter is to produce a barren classification . Edward Lhwyd , assistant and later successor to Dr Plot as curator of the Ashmolean Museum , had a more intimate acquaintance with fossils than any man in England and possibly in the world . this study , together with his scholarly researches into the Welsh and other Gaelic languages , formed his life &apos;s work . whenever he could afford it , he travelled widely to collect fossils and examine Welsh , Irish , Cornish and Breton manuscripts . he wrote the first illustrated textbook on fossils . his familiarity with them showed him that their resemblance to living things was no mere coincidence , but the inference that fossiliferous beds were elevated sea-floors was too much for him . he adopted the stray seed hypothesis , but in a spirit of candour he wrote to John Ray , I am not so fond of this hypothesis , as not to be sensible myself , that it lies open to a great many objections . still it was the best compromise he could come to . a poor museum curator with a salary of &amp;pound;40 per annum plus what he could get from selling fossils at a time when there was no great demand for them , was in no position to tilt at the thirty-nine articles . in rejecting the flood hypothesis , he says , in effect , that he demurs first because it is not in accord with the sacred scriptures and , secondly , because it does not accord with the facts . we may note the order of the objections . the doubts entertained by Leonardo da Vinci about the flood theory were explained away by John Woodward . in 1695 , he published a much-admired essay on the natural history of the earth . this was intended to repair imagined omissions in the Mosaic narrative in general and the account of Noah &apos;s flood in particular . in the essay , Woodward promises to give myself up to be guided wholly by matter of fact ; intending to steer that course which is thus agreed of all hands to be the best and surest : and not to offer anything but what hath due warrant from observations ; and those both carefully made and faithfully related . never can a promise made so fervently have been so lamentably forgotten in the course of a few pages . Woodward imagined that the flood had transformed the globe into a porridge-like mass and that the strata and the organic remains had subsided to stratify in layers according to their specific gravity . fantastic as the theory is , it becomes more so when we learn that it was acceptable to diluvialists in England and abroad for many years . with regard to the deluge , let me say that it is its world-wide occurrence which makes physical difficulties . an extensive , though local , inundation can easily be explained , but where did the water issue from and to where did it retreat to if there was enough to cover the whole surface ? I like Woodward &apos;s approach to this problem . for my part , he says , my subject does not necessarily oblige me to look after this water ; or to point forth the place whereunto &apos;t is now retreated . for when , from the sea-shells and other remains of the deluge , I shall have given you undeniable evidence that it did actually cover all parts of the earth ; it must needs follow that there was then water enough to do it , where it may be now hid , or whether it be still in being or not . one is tempted to say , when you come to an insurmountable obstacle look it squarely in the face and pass on , were it not that the argument is sound , granted the premises . as might have been expected , the hint of the marvellous and the untrammelled speculation emanating from fossil stones could not fail to attract the attention of that delightful character , John Aubrey . we turn to his natural history of Wiltshire confidently expecting some delicious things . now there is a great deal of truth in the notion that the geological environment is the primary factor in determining the character of a country ; not only topographically but historically . if the course of history is channelled by economics , then surely natural resources lie at the foundation of a country &apos;s development . and as men are the products of their times , the national character contains at least an element imposed upon it by the inanimate environment . Aubrey recognizes this on a very fine scale indeed . I quote : according to the several sorts of earth in England ( and so all the world over ) the indigenae are respectively witty or dull , good or bad . in north Wiltshire &amp;hellip; a dirty clayey country the indigenae speake drawling ; they are phlegmatique , skins pale and livid , slow and dull , heavy of spirit &amp;hellip; melancholy , contemplative and malicious ; by consequence whereof come more law suites out of north Wilts , at least double to the southern parts which , bye the bye , are composed of chalk . as to Aubrey &apos;s notions on fossils we simply record that he was much plagued with notions about earthquakes and their possible consequences on the earth &apos;s rotation ; and if he recognized that fossils give clear evidence that the earth hath been all covered over by water and when he often-times wishes for a mappe of England coloured according to the colours of the earths with marks of the fossiles and minerals , we conclude that he read his philosophical transactions and was acquainted with Hooke and Lister . as an example of the type of ingenuity provoked by a chance stimulus , we have the theory of the earth due to Whiston . in the latter years of the seventeenth century comets were in the air , as it were . the comet which led Newton to predict their parabolic orbits was visible between December 1680 and March 1681 . Halley &apos;s even more famous comet with a much less eccentric elliptical orbit , having a period of 75 to 76 years , was visible in 1682 . Whiston conjectures that Newton &apos;s comet was the same as that recorded in 44 B.C , A.D 531 and A.D 1106 which suggested a period of 575 years or so . he notes that , of two postulated dates for Noah &apos;s flood , namely , 2349 B.C and 2926 B.C , the discrepancy of 577 years is near enough to the assumed period of Newton &apos;s comet ; so that what ever date for the flood be accepted , the interval between it and 1681 was an integral multiple ( 7 or 8 ) of the postulated period of revolution of Newton &apos;s comet . note , however , that this period was not calculated from the observed visible portion of the comet &apos;s orbit , but inferred from certain coincidental dates . nevertheless , having convinced himself that a comet stood above the earth at the time of the deluge he invoked one to explain the other . the earth passed through the watery vapours of the comet &apos;s tail , and the floodgates of heaven were opened whilst its gravitational attraction fractured the earth &apos;s crust whence emerged the waters of the deep . the rest of Whiston &apos;s theory is according to Woodward with wholesale extinction of life and its stratification according to specific gravity in a porridgey mass which ultimately hardened into the stratified crust . the whole theory is ludicrous ; but if the rules of the game are first to invoke only recorded catastrophes and , secondly , to pay due regard to contemporary scientific fashions , then , surely , Whiston &apos;s attempt is a gem of its kind . Molyneux &apos;s suggestion that the extinction of the Irish elk was due to plague is perhaps a similar piece of opportunism . it is the type of explanation involved in explaining wet summers by atom-bomb explosions . amidst this welter of conflicting opinion the truth was there waiting to be disseminated . Robert Hooke in England and Nicholas Steno in Italy had published opinions which , had they been combined , would have opened up the subject 150 years before it was destined to flower . but these were writing in advance of their times and were consequently ignored . thus Hooke in 1688 in a discourse on earthquakes not only knew fossils for what they were but said that it would not be impossible to raise a chronology out of them . the occurrence of fossil turtles in the London clay of the Isle of Sheppey led him to conclude that England had formerly enjoyed a warmer climate than today . this was the first suggestion for an investigation into palaeoclimatology , a subject which is not completely established today , although inferences made from fossil faunas lie at the heart of its present development . nineteen years before Hooke &apos;s discourse , the implications of stratification had been announced to an indifferent scientific world by Steno . as founder of the science of crystallography , Steno would hardly confuse crystals with true fossils . it is a pity that their chronological possibilities were not added to his insight into stratification . but both Hooke and Steno threw out their geological ideas incidentally to their main pursuits ; and their contemporaries to whom geology was their main interest were unable to appreciate their foresight . for instance , their record of fossils at either a particular height above sea-level or depth below the surface in mines and quarries shows their ignorance of the subject of stratification . except in the rare horizontally bedded rocks these data have no significance chronologically . 