Chapter I: THE LOWLANDS OF BRITAIN. If a line be drawn across England from (5)

This 'wrong,' which Professor Darwin so seriously deprecated, has been committed not once, but again and again, in the history of this discussion. Lord Kelvin has never taken any notice of the strong body of evidence adduced by geologists and palæontologists in favour of a much longer antiquity than he is now disposed to allow for the age of the earth. His own three physical arguments have been successively re-stated, with such corrections and modifications as he has found to be necessary, and no doubt further alterations are in store for them.[90] He has cut off slice after slice from the allowance of time which at first he was prepared to grant for the evolution of geological history, his latest pronouncement being that 'it was more than twenty and less than forty million years, and probably much nearer twenty than forty.'[91] But in none of his papers is there an admission that geology and palæontology, though they have again and again raised their voices in protest, have anything to say in the matter that is worthy of consideration.

It is difficult satisfactorily to carry on a discussion in which your opponent entirely ignores your arguments, while you have given the fullest attention to his. In the present instance, geologists have most carefully listened to all that has been brought forward from the physical side. Impressed by the force of the physical reasoning, they no longer believe that they can make any demands they may please on past time. They have been willing to accept Lord Kelvin's original estimate of 100 millions of years as the period within which the history of life upon the planet must be comprised; while some of them have even sought in various ways to reduce that sum nearer to his lower limit. Yet there is undoubtedly a prevalent misgiving, whether in thus seeking to reconcile their requirements with the demands of the physicist they are not tying themselves down within limits of time which on any theory of evolution would have been insufficient for the development of the animal and vegetable kingdoms.

It is unnecessary to recapitulate before this Section of the British Association, even in briefest outline, the reasoning of geologists and palæontologists which leads them to conclude that the history recorded in the crust of the earth must have required for its transaction a much vaster period of time than that to which the physicists would restrict it.[92] Let me merely remark that the reasoning is essentially based on observations of the present rate of geological and biological changes upon the earth's surface. It is not, of course, maintained that this rate has never varied in the past. But it is the only rate with which we are familiar, which we can watch and in some degree measure, and which, therefore, we can take as a guide towards the comprehension and interpretation of the past history of our planet.

It may be, and has often been, said that the present scale of geological and biological processes cannot be accepted as a reliable measure for the past. Starting from the postulate, which no one will dispute, that the total sum of terrestrial energy was once greater than it is now and has been steadily declining, the physicists have boldly asserted that all kinds of geological action must have been more vigorous and rapid during bygone ages than they are to-day; that volcanoes were more gigantic, earthquakes more frequent and destructive, mountain-upthrows more stupendous, tides and waves more powerful, and commotions of the atmosphere more violent, with more ruinous tempests and heavier rainfall. Assertions of this kind are temptingly plausible and are easily made. But it is not enough that they should be made; they ought to be supported by some kind of evidence to show that they are founded on actual fact and not on mere theoretical possibility. Such evidence, if it existed, could surely be produced. The chronicle of the earth's history, from a very early period down to the present time, has been legibly written within the sedimentary formations of the terrestrial crust. Let the appeal be made to that register. Does it lend any support to the affirmation that the geological processes are now feebler and slower than they used to be? If it does, the physicists, we might suppose, would gladly bring forward its evidence as irrefragable confirmation of the soundness of their contention. But the geologists have found no such confirmation. On the contrary, they have been unable to discover any indication that the rate of geological causation has ever, on the whole, greatly varied during the time which has elapsed since the deposition of the oldest stratified rocks. They do not assert that there has been no variation, that there have been no periods of greater activity, both hypogene and epigene. But they maintain that the demonstration of the existence of such periods has yet to be made. They most confidently affirm that whatever may have happened in the earliest ages, throughout the whole vast succession of sedimentary strata nothing has yet been detected which necessarily demands that more violent and rapid action which the physicists suppose to have been the order of nature during the past.

So far as the potent effects of prolonged denudation permit us to judge, the latest mountain-upheavals were at least as stupendous as any of older date whereof the basal relics can yet be detected. They seem, indeed, to have been still more gigantic than these. It may be doubted, for example, whether among the vestiges that remain of Mesozoic or Palæozoic mountain-chains, any instance can be found so colossal as those of Tertiary times, such as the Alps. No volcanic eruptions of the older geological periods can compare in extent or volume with those of Tertiary and recent date. The plication and dislocation of the terrestrial crust are proportionately as conspicuously displayed among the younger as among the older formations, though the latter, from their greater antiquity, have suffered during a longer time from the renewed disturbances of successive periods.

As regards evidence of greater violence in the surrounding envelopes of atmosphere and ocean, we seek for it in vain among the stratified rocks. One of the very oldest formations in Europe, the Torridon Sandstone of North-West Scotland, presents us with a picture of long-continued sedimentation, such as may be seen in progress now round the shores of many a mountain-girdled lake. In that venerable deposit, the enclosed pebbles are not mere angular blocks and chips, swept by a sudden flood or destructive tide from off the surface of the land, and huddled together in confused heaps over the floor of the sea. They have been rounded and polished by the quiet operation of running water, as stones are rounded and polished now in the channels of brooks or on the shores of lake and sea. They have been laid gently down above each other, layer over layer, with fine sand sifted in between them, and this deposition has taken place along shores which, though the waters that washed them have long since disappeared, can still be followed for mile after mile across the mountains and glens of the North-West Highlands. So tranquil were these waters that their gentle currents and oscillations sufficed to ripple the sandy floor, to arrange the sediment in laminæ of current-bedding, and to separate the grains of sand according to their relative densities. We may even now trace the results of these operations in thin darker layers and streaks of magnetic iron, zircon, and other heavy minerals, which have been sorted out from the lighter quartz-grains, as layers of iron-sand may be seen sifted together by the tide along the upper margins of many of our sandy beaches at the present day.

In the same ancient formation there occur also various intercalations of fine muddy sediment, so regular in their thin alternations, and so like those of younger formations, that we cannot but hope and expect that they may eventually yield remains of organisms which, if found, would be the earliest traces of life in Europe.

It is thus abundantly manifest that even in the most ancient of the sedimentary registers of the earth's history, not only is there no evidence of colossal floods, tides and denudation, but there is incontrovertible proof of continuous orderly deposition, such as may be witnessed to-day in any quarter of the globe. The same tale, with endless additional details, is told all through the stratified formations, down to those which are in the course of accumulation at the present day.

Not less important than the stratigraphical is the palæontological evidence in favour of the general quietude of the geological processes in the past. The conclusions drawn from the nature and arrangement of the sediments are corroborated and much extended by the structure and manner of entombment of the enclosed organic remains. From the time of the very earliest fossiliferous formations there is nothing to show that either plants or animals have had to contend with physical conditions of environment different, on the whole, from those in which their successors now live. The oldest trees, so far as regards their outer form and internal structure, betoken an atmosphere neither more tempestuous nor obviously more impure than that of to-day. The earliest corals, sponges, crustaceans, mollusks, and arachnids were not more stoutly constructed than those of later times, and they are found grouped together among the rocks as they lived and died, with no apparent indication that any violent commotion of the elements tried their strength when living or swept away their remains when dead.

But, undoubtedly, most impressive of all the palæontological data is the testimony borne by the grand succession of organic remains among the stratified rocks as to the vast duration of time required for their evolution. Professor Poulton has treated this branch of the subject with great fulness and ability (p. 216). We do not know the present average rates of organic variation, but all the available evidence goes to indicate their extreme slowness. They may conceivably have been more rapid in the past, or they may have been liable to fluctuations according to vicissitudes of environment.[93] But those who assert that the rate of biological evolution ever differed materially from what it may now be inferred to be, ought surely to bring forward something more than mere assertion in their support. In the meantime, the most philosophical course is undoubtedly followed by those biologists who in this matter rest their belief on their own experience among recent and fossil organisms.

So cogent do these geological and palæontological arguments appear, to those at least who have taken the trouble to master them, that they are worthy of being employed, not in defence merely, but in attack. It seems to me that they may be used with effect in assailing the stronghold of speculation and assumption in which our physical friends have ensconced themselves and from which, with their feet, as they believe, planted well within the interior of the globe and their heads in the heart of the sun, they view with complete unconcern the efforts made by those who endeavour to gather the truth from the surface and crust of the earth. That portion of the records of terrestrial history which lies open to our investigation has been diligently studied in all parts of the world. A vast body of facts has been gathered together from this extended and combined research. The chronicle registered in the earth's crust, though not complete, is legible and consistent. From the latest to the earliest of its chapters the story is capable of clear and harmonious interpretation by a comparison of its pages with the present condition of things. We know infinitely more of the history of this earth than we do of the history of the sun. Are we then to be told that this knowledge so patiently accumulated from innumerable observations and so laboriously co-ordinated and classified, is to be held of none account in comparison with the conclusions of physical science in regard to the history of the central luminary of our system? These conclusions are founded on assumptions which may or may not correspond with the truth. They have already undergone revision, and they may be still further modified as our slender knowledge of the sun, and of the details of its history, is increased by future investigation. In the meantime, we decline to accept them as a final pronouncement of science on the subject. We place over against them the evidence of geology and palæontology, and affirm that unless the deductions we draw from that evidence can be disproved, we are entitled to maintain them as entirely borne out by the testimony of the rocks.

Until, therefore, it can be shown that geologists and palæontologists have misinterpreted their records, they are surely well within their logical rights in claiming as much time for the history of this earth as the vast body of evidence accumulated by them demands. So far as I have been able to form an opinion, one hundred millions of years would suffice for that portion of the history which is registered in the stratified rocks of the crust. But if the palæontologists find such a period too narrow for their requirements, I can see no reason on the geological side why they should not be at liberty to enlarge it as far as they may find to be needful for the evolution of organised existence on the globe. As I have already remarked, it is not the length of time which interests us so much as the determination of the relative chronology of the events which were transacted within that time. As to the general succession of these events, there can be no dispute. We have traced its stages from the bottom of the oldest rocks up to the surface of the present continents and the floor of the present seas. We know that these stages have followed each other in orderly advance, and that geological time, whatever limits may be assigned to it, has sufficed for the passage of the long stately procession.

We may, therefore, well leave the dispute about the age of the earth to the decision of the future. In so doing, however, I should be glad if we could carry away from it something of greater service to science than the consciousness of having striven our best in a barren controversy, wherein concession has all to be on one side and the selection of arguments entirely on the other. During these years of prolonged debate I have often been painfully conscious that in this subject, as in so many others throughout the geological domain, the want of accurate numerical data is a serious hindrance to the progress of our science. Heartily do I acknowledge that much has been done in the way of measurement and experiment for the purpose of providing a foundation for estimates and deductions. But infinitely more remains to be accomplished. The field of investigation is almost boundless, for there is hardly a department of geological dynamics over which it does not extend. The range of experimental geology must be widely enlarged, until every process susceptible of illustration or measurement by artificial means has been investigated. Field-observation needs to be supplemented where possible by instrumental determination, so as to be made more precise and accurate, and more capable of furnishing reliable numerical statistics for practical as well as theoretical deductions.

The subject is too vast for adequate treatment here. But let me illustrate my meaning by selecting a few instances where the adoption of these more rigid methods of inquiry might powerfully assist us in dealing with the rates of geological processes and the value of geological time. Take, for example, the wide range of lines of investigation embraced under the head of Denudation. So voluminous a series of observations has been made in this subject, and so ample is the literature devoted to it, that no department of geology, it might be thought, has been more abundantly and successfully explored. Yet if we look through the pile of memoirs, articles and books, we cannot but be struck with the predominant vagueness of their statements, and with the general absence of such numerical data determined by accurate, systematic, and prolonged measurement as would alone furnish a satisfactory basis for computations of the rate at which denudation takes place. Some instrumental observations of the greatest value have indeed been made, but, for the most part, observations of this kind have been too meagre and desultory.

A little consideration will show that in all branches of the investigation of denudation opportunities present themselves on every side of testing, by accurate instrumental observation and measurement, the rate at which some of the most universal processes in the geological mechanism of our globe are carried on.

It has long been a commonplace of geology that the amount of the material removed in suspension and solution by Rivers furnishes a clue to the rate of denudation of the regions drained by the rivers. But how unequal in value, and generally how insufficient in precision, are the observations on this topic! A few rivers have been more or less systematically examined, some widely varying results have been obtained from the observations, and while enough has been gained to show the interest and importance of the method of research, no adequate supply of materials has been gathered for the purposes of wide, accurate deduction and generalisation. What we need is a carefully organised series of observations carried out on a uniform plan, over a sufficient number of years, not for one river only, but for all the important rivers of a country, and indeed for all the greater rivers of each continent. We ought to know as accurately as possible the extent of the drainage-area of each river, the relations of river-discharge to rainfall and to other meteorological as well as topographical conditions; the variation in the proportions of mechanical and chemical impurities in the river-water according to geological formations, form of the ground, season of the year and climate. The whole geological _régime_ of each river should be thoroughly studied. The admirable report of Messrs. Humphreys and Abbot on the 'Physics and Hydraulics of the Mississippi,' published in 1861, might well serve as a model for imitation, though these observers necessarily occupied themselves with some questions which are not specially geological, and did not enter into others on which, as geologists, we should now gladly have further information.

Again, the action of Glaciers has still less been subjected to prolonged and systematic observation. The few data already obtained are so vague that we may be said to be still entirely ignorant of the rate at which glaciers are wearing down their channels and contributing to the denudation of the land. The whole of this inquiry is eminently suitable for combined research. Each stream or glacier, or each well-marked section of one, might become the special inquiry of a single observer, who would soon develop a paternal interest in his valley and vie with his colleagues of other valleys in the fulness and accuracy of his records.

Nor is our information respecting the operations of the Sea much more precise. Even in an island like Great Britain, where the waves and tides effect so much change within the space of a human life-time, the estimates of the rate of advance or retreat of the shore-line are based for the most part on no accurate determinations. It is satisfactory to be able to announce that the Council of this Association has formed a Committee for the purpose of obtaining full and precise information regarding alterations of our coasts, and that, with the sanction of the Lords of the Admiralty, the co-operation of the Coast-guard throughout the three kingdoms has been secured. We may therefore hope to be eventually in possession of trustworthy statistics on this interesting subject.[94]

The Denudation of the Surface of the Land by the combined agency of the subaërial forces of decay is a problem which has been much studied, but in regard to whose varying rates of advance not much has been definitely ascertained. The meteorological conditions under which it takes place differ materially according to latitude and climate, and doubtless its progress is equally variable. An obvious and useful source of information in regard to atmospheric denudation is to be found in the decay of the material of buildings of which the time of erection is known, and in dated tombstones. Twenty years ago I called attention to the rate at which marble gives way in such a moist climate as ours, and cited the effects of subaërial waste as these can be measured on the monuments of our graveyards and cemeteries.[95] I would urge upon town-geologists, and those in the country who have no opportunities of venturing far afield, that they may do good service by careful scrutiny of ancient buildings and monuments. In the churchyards they will find much to occupy and interest them, not, however, like Old Mortality, in repairing the tombstones, but in tracing the ravages of the weather upon them, and in obtaining definite measures of the rate of their decay.

The conditions under which subaërial disintegration is effected in arid climates, and the rate of its advance, are still less known, seeing that most of our information is derived from the chance observations of passing travellers. Yet this branch of the subject is not without importance in relation to the denudation not only of the existing terrestrial surface but of the lands of former periods, for there is evidence of more than one arid epoch in geological history. Here, again, a diligent examination of ancient buildings and monuments might afford some, at least, of the required data. In such a country as Egypt, for instance, it might eventually be possible to determine from a large series of observations what has been the average rate of surface-disintegration of the various kinds of stone employed in human constructions that have been freely exposed to the air for several thousand years.

Closely linked with the question of denudation is that of the Deposition of the material worn away from the surface of the land. The total amount of sediment laid down must equal the amount of material abstracted, save in so far as the soluble portions of that material are retained in solution in the sea. But we have still much to learn as to the conditions, and especially as to the rate, of sedimentation. Nor does there appear to be much hope of any considerable increase to our knowledge until the subject is taken up in earnest as one demanding and justifying a prolonged series of well-planned and carefully executed observations. We have yet to discover the different rates of deposit, under the varying conditions in which it is carried on in lakes, estuaries, and the sea. What, for instance, would be a fair average for the rate at which the lakes of each country of Europe are now being silted up? If this rate were ascertained, and if the amount of material already deposited in these basins were determined, we should be in possession of data for estimating not only the probable time when the lakes will disappear, but also the approximate date at which they came into existence.

But it is not merely in regard to epigene changes that further more extended and concerted observation is needed. Even among Subterranean movements there are some which might be watched and recorded with far more care and continuity than have ever been attempted. The researches of Professor George Darwin and others have shown how constant are the tremors, minute but measureable, to which the crust of the earth is subject.[96] Do any of these phenomena indicate displacement of the crust, and, if so, what in the lapse of a century is their cumulative effect on the surface of the land?

More momentous in their consequences are the disturbances which traverse mountain-chains and find their most violent expression in shocks of Earthquake. The effects of such shocks have been studied and recorded in many parts of the world, but their causes are only partially understood. Are the disturbances due to a continuation of the same operation which at first gave birth to the mountains? Should they be regarded as symptoms of growth or of collapse? Are they accompanied with even the slightest amount of elevation or depression? We cannot tell. But these questions are probably susceptible of some more or less definite answer. It might be possible, for instance, to determine with extreme precision the heights above a given datum of various fixed points along such a chain as the Alps, and by a series of minutely accurate measurements to detect any upward or downward deviation from these heights. It is quite conceivable that throughout the whole historical period some deviation of this kind has been going on, though so slowly, or by such slight increments at each period of renewal, as to escape ordinary observation. We might thus learn whether, after an Alpine earthquake, an appreciable difference of level is anywhere discoverable, whether the Alps as a great mountain-chain are still growing or are now subsiding, and we might be able to ascertain the rate of the movement. Although changes of this nature may have been too slight during human experience to be ordinarily appreciable, their very insignificance seems to me to supply a strong reason why they should be sought for and carefully measured. They would not tell us, indeed, whether a mountain-chain was called into being in one gigantic convulsion, or was raised at wide intervals by successive uplifts, or was slowly elevated by one prolonged and continuous movement. But they might furnish us with suggestive information as to the rate at which upheaval or depression of the terrestrial crust is now going on.

The vexed questions of the origin of Raised Beaches and Sunk Forests might in like manner be elucidated by well-devised measurements. It is astonishing upon what loose and unreliable evidence the elevation or depression of coast-lines has often been asserted. On shores where proofs of a recent change of level are observable it would not be difficult to establish by accurate observation whether any such movements are taking place now, and, if they are, to determine their rate. The old attempts of this kind along the coasts of Scandinavia might be resumed with far more precision and on a much more extended scale. Methods of instrumental research have been vastly improved since the days of Celsius and Linnæus. Mere eye-observations would not supply sufficiently accurate results. When the datum-line has been determined with rigorous accuracy, the minutest changes of level, such as would be wholly inappreciable to the senses, might be detected and recorded. If such a system of watch were maintained along coasts where there is reason to believe that some change in the relative level of sea and land is taking place, it would be possible to follow the progress of the movement and to determine its rate.

But I must not dwell longer on examples of the advantages which geology would gain from a far more general and systematic adoption of methods of experiment and measurement in elucidation of the problems of the science. I have referred to a few of those which have a more special bearing on the question of geological time, but it is obvious that the same methods might be extended into almost every branch of geological dynamics. While we gladly and gratefully recognise the large amount of admirable work that has already been done by the adoption of these practical methods, from the time of Hall, the founder of experimental geology, down to our own day, we cannot but feel that our very appreciation of the gain which the science has thus derived increases the desire to see the practice still further multiplied and extended. I am confident that it is in this direction more than in any other that the next great advances of geology are to be anticipated.

While much may be done by individual students, it is less to their single efforts than to the combined investigations of many fellow-workers that I look most hopefully for the accumulation of data towards the determination of the present rate of geological changes. I would, therefore, commend this subject to the geologists of this and other countries as one in which individual, national, and international co-operation might well be enlisted. We already possess an institution which seems well adapted to undertake and control an enterprise of the kind suggested. The International Geological Congress, which brings together our associates from all parts of the globe, would confer a lasting benefit on the science if it could organise a system of combined observation in any single one of the departments of inquiry which I have indicated or in any other which might be selected. We need not at first be too ambitious. The simplest, easiest, and least costly series of observations might be chosen for a beginning. The work might be distributed among the different countries represented in the Congress. Each nation would be entirely free in its selection of subjects for investigation, and would have the stimulus of co-operation with other nations in its work. The Congress will hold its triennial gathering next year in Paris, and if such an organisation of research as I have suggested could then be inaugurated a great impetus would thereby be given to geological research, and France, again become the birthplace of another scientific movement, would acquire a fresh claim to the admiration and gratitude of geologists in every part of the globe.[97]

FOOTNOTES:

[71] Presidential Address to the Geological Section of the British Association for the Advancement of Science at the Dover Meeting 1899.

[72] _Theory of the Earth_, vol. i. p. 108.

[73] _Op. cit._, vol. i. p. 173, _note_.

[74] _Op. cit._, vol. ii. p. 329.

[75] _Op. cit._, vol. i. p. 200.

[76] _Theory of the Earth_, vol. ii. p. 205.

[77] _Op. cit._, vol. i. p. 44.

[78] _Illustrations of the Huttonian Theory_, § 118.

[79] _Trans. Roy. Soc. Edin._, vol. xxiii. (1862).

[80] _Proc. Roy. Soc. Edin._, vol. v. p. 512 (Dec. 18, 1865).

[81] _Trans. Geol. Soc. Glasgow_, vol. iii. (February, 1868), pp. 1, 16.

[82] 'The Age of the Earth,' being the Annual Address to the Victoria Institute, June 2, 1897. _Phil. Mag._, January, 1899, p. 66.

[83] _Recent Advances in Physical Science_, p. 174.

[84] Presidential Address. _Quart. Journ. Geol. Soc._, 1869.

[85] _Trans. Geol. Soc. Glasgow_, vol. iii. (March 26, 1868), p. 189. Sir W. Thomson acknowledged my adhesion in his reply to Huxley's criticism. _Op. cit._, p. 221.

[86] Darwin's _Life and Letters_, vol. iii. pp. 115, 146.

[87] _Rep. Brit. Assoc._, 1886, p. 517.

[88] _Nature_, vol. li. p. 585, April 18, 1895.

[89] _Rep. Brit. Assoc._, 1886, p. 518.

[90] October 1904. Since this Address was given the subject of radio-activity has assumed high importance in reference to questions connected with the evolution of the cosmos. Thus Prof. George Darwin, in view of the newly discovered properties of radium, has stated that he sees 'no reason for doubting the possibility of augmenting the estimates of solar heat, as derived from the theory of gravitation, by some such factor as ten or twenty' (_Nature_, 24th Sept., 1903). The same opinion is shared by Prof. Joly, who points out that the establishment of the observed gradient of temperature from the earth's surface inward 'may have been deferred indefinitely during the exhaustion of stores of radium and similar bodies at greater or shallower depths' (_Nature_, 1st Oct., 1903). More recently Prof. Rutherford, who has taken so leading a part in the discussion of radio-activity, has made the following statement: 'I think we may conclude that the present rate of loss of heat of the earth might have continued unchanged for long periods of time in consequence of the supply of heat from radio-active matter in the earth. It thus seems probable that the earth may have remained for very long intervals of time at a temperature not very different from that observed to-day, and that in consequence the time during which the earth has been at a temperature capable of supporting the presence of animal and vegetable life may be very much longer than the estimate made by Lord Kelvin from other data' (_Radio-activity_, Cambridge, 1904, p. 346). Thus two of the three physical arguments are impugned on new grounds, and the forecast of Prof. Darwin is shown to have been reasonable when in 1886 he said: 'Although speculations as to the future course of science are usually of little avail, yet it seems as likely that meteorology and geology will pass the word of command to cosmical physics as the converse.'

[91] _The Age of the Earth_, Presidential Address to the Victoria Institute for 1897, p. 10; also in _Phil. Mag._, January 1899.

[92] The geological arguments are briefly given in my Presidential Address to the British Association at the Edinburgh Meeting of 1892 (_ante_ p. 182). The biological arguments were well stated, and in some detail, by Professor Poulton in his Address to the Zoological Section of the Association at the Liverpool Meeting of 1896.

[93] See an interesting and suggestive paper by Professor Le Conte on 'Critical Periods in the History of the Earth,' _Bull. Dept. Geology, University of California_, vol. i. (1895), p. 313; also one by Professor Chamberlin on 'The Ulterior Basis of Time-divisions and the Classification of Geological History,' _Journal of Geology_, vol. vi. (1898), p. 449.

[94] The first Report of this Committee was submitted to the Southport meeting of the Association in 1903. But the question is one of such importance in view of the rapidity with which some parts of our coast are in course of demolition that it deserves to be taken up as a national investigation. The country at large should contribute to the expense of applying the best means for arresting the waste of its shores. At present the contest has to be carried on by the riparian proprietors, who are often quite unable adequately to cope with it. _October_, 1904.

[95] _Proc. Roy. Soc. Edin._, vol. x. (1879-80) p. 518.

[96] _Report Brit. Assoc._, 1882, p. 95.

[97] The hope here expressed has so far been realised by the appointment of a Committee of the Geological Congress at Paris in 1900 and the renewal and extension of this Committee at the following Meeting held in Vienna in 1903. The subjects of Earthquakes, Movements of elevation or depression in mountain chains and measurements of the value of Gravity were especially proposed for investigation. The recommendations of the Committee were approved by the International Association of Academies in London in the summer of 1904 and steps were then taken in the direction of international co-operation in each of the subjects suggested. _Note added_, October, 1904.

VII

The Life and Letters of Charles Darwin[98]

By the universal consent of mankind, the name of Charles Darwin was placed, even during his lifetime, among those of the few great leaders who stand forth for all time as the creative spirits that have founded and legislated for the realm of Science. It is too soon to estimate with precision the full value and effect of his work. The din of controversy that rose around him has hardly yet died down, and the influence of the doctrines he propounded is extending into so many remote departments of human inquiry, that a generation or two may require to pass away before his true place in the history of thought can be definitely fixed. But the judgment of his contemporaries as to his proud pre-eminence is not likely ever to be called in question. He is enrolled among the _Dii Majorum Gentium_, and there he will remain to the end of the ages. When he was laid beside the illustrious dead in Westminster Abbey, there arose far and wide a lamentation as of personal bereavement. Thousands of mourners who knew only his writings, and judged of the gentleness and courtesy of his nature from these and from such hearsay reports as passed outwards from the privacy of his country home, grieved as for the loss of a dear friend. It is remarkable that probably no scientific man of his day was personally less familiar to the mass of his fellow-countrymen. He seemed to shun all the usual modes of contact with them. His weak health, domestic habits, and absorbing work kept him in the seclusion of his own quiet household. In later years his face was seldom to be seen at the meetings of scientific societies, or at those gatherings where the discoveries of science are expounded to more popular audiences. He shrank from public controversy, although no man was ever more vigorously attacked and more completely misrepresented. Nevertheless, when he died, the affectionate regret that followed him to the grave came not alone from his own personal friends, but from thousands of sympathetic mourners in all parts of the world, who had never known or seen him. Men had ample material for judging of his work, and in the end had given their judgment with general acclaim. Of the man himself, however, they could know but little, yet enough of his character shone forth in his work to indicate its tenderness and goodness. Men instinctively felt him to be in every way one of the great ones of the earth, whose removal from the living world leaves mankind poorer in moral worth as well as in intellect. So widespread has been this conviction, that the story of his life has been eagerly longed for. It might contain no eventful incidents, but it would reveal the man as he was, and show the method of his working and the secret of his greatness.

At last, five years and a half after his death, the long expected Memoir has made its appearance. The task of preparing it was undertaken by his son, Mr. Francis Darwin, who, having for the last eight years of his father's life acted as his assistant, was specially qualified to put the world in possession of a true picture of the inner life of the great naturalist. Most biographies are too long, but, in the present case, the three goodly volumes will be found to contain not a page too much. The narrative is absorbingly interesting from first to last. The editor, with excellent judgment, allows Darwin himself, as far as possible, to tell his own story in a series of delightful letters, which bring us into the very presence of the earnest student and enthusiastic explorer of Nature.

Charles Darwin came of a family which from the beginning of the sixteenth century had been settled on the northern borders of Lincolnshire. Several of his ancestors had been men of literary taste and scientific culture, the most noted of them being his grandfather, Erasmus Darwin, the poet and philosopher. His father was a medical man in large practice at Shrewsbury, and his mother, a daughter of Josiah Wedgewood of Etruria. Some interesting reminiscences are given of the father, who must have been a man of uncommon strength of character. He left a large fortune, and thus provided for the career which his son was destined to fulfil. Of his own early life and later years, Darwin has left a slight but most interesting sketch in an autobiographical fragment, written late in life for his children, and without any idea of its ever being published. From this outline we learn that he was born at Shrewsbury on the 12th of February, 1809. Shortly before his mother's death, in 1817, he was sent, when eight years old, to a day-school in his native town. But even in the period of childhood he had chosen the favourite occupation of his life; 'my taste for natural history,' he says, 'and more especially for collecting, was well developed. I tried to make out the names of plants, and collected all sorts of things--shells, seals, franks, coins and minerals. The passion for collecting which leads a man to be a systematic naturalist, a virtuoso, or a miser, was very strong in me, and was clearly innate, as none of my sisters or brother ever had this taste.' According to his own account, he was 'in many ways a naughty boy.' But there must have been so much fun and kind-heartedness in his transgressions, that neither parents nor teachers could have been very seriously offended by his pranks. What, for instance, could be said to a boy who would gravely pretend to a schoolfellow that he could produce variously tinted flowers by watering them with coloured fluids, or who gathered a quantity of fruit from his father's trees, hid it in the shrubbery, and then ran off to announce his discovery of a robbery; or who, after beating a puppy, felt such remorse that the memory of the act lay heavy on his conscience and remained with him to old age? In 1818 he was placed under Dr. Butler in Shrewsbury School, where he continued to stay for seven years until 1825, when he was sixteen years old. He confesses that the classical training at that seminary was useless to him, and that the school as a means of education was, so far as he was concerned, simply a blank. Verse-making, and learning by heart so many lines of Latin or Greek, seem to have been the occupations of school that specially dwelt in his memory, the sole pleasure he could recall being the reading of some of Horace's Odes. He describes, however, the intense satisfaction with which he followed the clear geometrical proofs of Euclid, and the pleasure he took in sitting for hours in an old window of the school reading Shakespeare. He made acquaintance, too, with the poems of Thomson, Byron and Scott, but confesses that in later life, to his great regret, he lost all pleasure from poetry of any kind, even from Shakespeare.

The first book that excited in him a wish to travel was a copy of the _Wonders of the World_ in the possession of a schoolfellow, which he read with some critical discrimination, for he used to dispute with other boys about the veracity of its statements. Nothing in the school-life could daunt his ardour in the pursuit of natural history. He continued to be a collector, and began to show himself an attentive observer of insects and birds. White's _Selborne_, which has started so many naturalists on their career, stimulated his zeal, and he became so fond of birds as to wonder in his mind why every gentleman did not become an ornithologist. Nor were his interests confined to the biological departments of Nature. With his brother, who had made a laboratory in the garden tool-house, he worked hard at chemistry, and learned for the first time the meaning of experimental research. These extra-scholastic pursuits, which he declares to have been the best part of his education at school, came somehow to be talked of by his companions, who consequently nicknamed him 'Gas'; and Dr. Butler, when he heard of them, rebuked the young philosopher, for 'wasting time on such useless subjects,' and called him a 'poco curante.' It was evident to his father that further attendance at Shrewsbury School would not advance young Darwin's education, and he was accordingly sent in 1825, when he was a little over sixteen years old, to join his elder brother, who was attending the medical classes of the University of Edinburgh. It was intended that he should begin the study of medicine, and qualify himself for that profession; but he had already discovered that a sufficient competence would eventually come to him to enable him to live in some comfort and independence. So he went to the lectures with no very strong determination to get from them as much good as if he knew that his living was to depend on his success. He found them 'intolerably dull,' and records in maturer years his deliberate conviction that 'there are no advantages, and many disadvantages, in lectures compared with reading.' That he did not conquer his repugnance to the study of anatomy in particular is remarkable, when we consider how strong already was his love of biology, and how wholly it dominated his later life. Tenderness of nature seems to have had much to do with his repugnance. He could not bear the sight of suffering; the cases in the clinical wards in the Infirmary distressed him, and after bringing himself to attend for the first time the operating theatre, he rushed away before the operations were completed and never went back. But he afterwards came to regard as one of the greatest evils of his life that he had not been urged to conquer his disgust and make himself practically familiar with the details of human anatomy. It is curious, too, to learn with what aversion he regarded the instructions of the Professor of Natural History in the University. Jameson could certainly kindle, or at least stimulate, enthusiasm in some young souls, as the brilliant band of naturalists trained under him in Edward Forbes' time sufficiently proved. But to others he undoubtedly was, what Darwin describes him, 'incredibly dull.' If the professorial teaching was defective, however, the loss seems to have been in good measure made up by the companionship of fellow-students of kindred tastes, with whom the future naturalist explored the neighbourhood of Edinburgh. Collecting animals from the tidal pools of the estuary of the Forth, and accompanying the Newhaven fishermen in their dredging voyages for oysters, he found plenty of material for study, and employed himself in dissecting as well as he could. In the course of these observations he made his first recorded discovery, which was 'that the so-called ova of _Flustra_ had the power of independent movement by means of cilia, and were, in fact, larvae.' As a part of his love of Nature and out-of-door employments, he became an ardent sportsman, rose even long before day, in order to reach the ground betimes, and went to bed with his shooting boots placed open close beside him, that not a moment might be lost in getting into them.

When two sessions had been passed at Edinburgh and no great zeal appeared for the medical profession, Darwin's father proposed to him that he should become a clergyman, for it was out of the question that the young student should be allowed to turn into an idle sporting man, as he bade fair to do. After some time given to reflection on this momentous change in his career, Darwin, who 'did not then in the least doubt the strict and literal truth of every word in the Bible,' agreed to the proposal. Many years afterwards, when he had risen to fame, and his photograph was the subject of public discussion at a German psychological society, he was declared by one of the speakers to have 'the bump of reverence developed enough for ten priests.' So that in one respect, as he says of himself, he was well fitted to be a clergyman. In another and more serious qualification, however, he found himself lamentably and almost incredibly deficient. If his two years at Edinburgh had not added much to his stock of professional knowledge, they seem to have driven out of his head what slender share of classical learning he had imbibed at Shrewsbury. He had actually forgotten some of the Greek letters, and had to begin again, therefore, at the very beginning. But after a few months of preliminary training he found himself able to proceed to Cambridge in the early part of the year 1828, when he was now nearly nineteen years of age. So far as concerned academical studies, the three years at the University were, in his own opinion, as much wasted time as his residence at Edinburgh or his life at school had been. He attempted mathematics, which he found repugnant. In classics he did as little as he could; but in the end he took his B.A. degree, and got the tenth place on the list of those who did not go in for honours. The disgust for geology with which the Wernerian doctrines at Edinburgh had inspired him, prevented him from becoming a pupil of Sedgwick. It is curious to speculate on what might have been his ultimate bent had he then come under the spell of that eloquent, enthusiastic, and most lovable man. Not improbably he would have become an ardent geologist, dedicating more exclusively to that science the genius and industry which he devoted to biology and to natural history as a whole.

Some of the incidents of his Cambridge life which he records are full of interest in their bearing on his future career. Foremost among them stands the friendship which he formed with Professor Henslow, whose lectures on botany he attended. He joined in the class excursions, and found them delightful. But still more profitable to him were the long and almost daily walks which he enjoyed with his teacher during the latter half of his time at Cambridge. Henslow's wide range of acquirement, his modesty, unselfishness, courtesy, gentleness and piety, fascinated Darwin and exerted on him an influence which, more than anything else, tended to shape his whole future life. The love of travel, which had been kindled by his boyish reading, now took a deeper hold of him as he read Humboldt's _Personal Narrative_, and Herschel's _Introduction to the Study of Natural Philosophy_. He determined to visit Teneriffe, and even went so far as to inquire about ships. But his desire was soon to be gratified in a far other and more comprehensive voyage. At the close of his college life he was fortunate enough, through Henslow's good offices, to accompany Sedgwick in a geological excursion in North Wales. There can be little doubt that this short trip sufficed to efface the dislike of geology which he had conceived at Edinburgh, and to show him how much it was in his own power to increase the sum of geological knowledge. To use his own phrase, he began to 'work like a tiger' at geology.

But he now had reached the main turning-point of his career. On returning home from his ramble with Sedgwick he found a letter from Henslow, telling him that Captain Fitz-Roy, who was about to start on the memorable voyage of the _Beagle_, was willing to give up part of his own cabin to any competent young man who would volunteer to go with him without pay as a naturalist. The post was offered to Darwin, and after some natural objections on the part of his father, who thought that such a wild scheme would be disreputable to his character as a future clergyman, was accepted. His intention of becoming a clergyman, and his father's wish that he should do so, were never formally given up; but from this time onward they dropped out of sight. The _Beagle_ weighed anchor from Plymouth on the 27th of December, 1831, and returned on the 2nd of October, 1836.

Of the voyage in the _Beagle_ and its scientific fruits Darwin himself has left ample record in his _Journal of Researches_, and in the various memoirs on special branches of research which he afterwards published. The editor of the Biography has wisely refrained from repeating the story of this important part of his father's life. But he has given a new charm to it by printing a few of the letters written during the voyage, which help us to realise still more vividly the life and work of the naturalist in his circumnavigation of the world. We can picture him in his little cabin, working diligently at the structure of marine creatures, but driven every now and then to lie down as a relief from sea-sickness, which worried him during the voyage and which was thought by some to have permanently injured his health. We see him littering the deck with his specimens, and thereby raising the indignation of the prim first lieutenant, who declared he would like to turn the naturalist and his mess 'out of the place,' but who, in spite of this want of sympathy, was recognised by Darwin as a 'glorious fellow.' We watch him in the tropical forests and in the calm glories of the tropical nights with the young officers listening to his exposition of the wonders of Nature around them. And, above all, we mark his exuberant enthusiasm in the new aspects of the world that came before him, his gentleness, unfailing good-nature and courtesy, that endeared him alike to every officer and sailor in the ship. The officers playfully dubbed him their 'dear old philosopher,' and the men called him 'our flycatcher.'