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 ^x'xix^i) Jlssociaiion for f^c Hduanccmcnf ^ ^ 
 
 of Science. 
 
 ,-,^'^" 
 
 
 v^^ 
 
 ADDRESS 
 
 ^^Sj'"^'"'' ' * — iy "^ 
 
 y 
 
 BY 
 
 SIR J. WILLIAM DAWSON, 
 
 C.M.G., M.A., LL.D., F.R.S., F.G.S., Principal and V-'ce-Chancellor 
 of McGill University, Montreal, Canada, 
 
 PRESIDENT. 
 
 Twenty-one years have passed away since the last meeting cf the British 
 Association in this great central city of England. At the third Birming- 
 ham meeting — that of 1865 — I had the pleasure of being present, and had 
 the honour of being one of the Vice-Presidents of Section 0. At that 
 meeting my friend John Phillips, one of the founders of the Association, 
 occupied the Presidential chair, and I cannot better introduce what I have 
 to say this evening than by the eloquent words in which he then 
 addressed you. 'Assembled for the third time in this busy centre of 
 industrious England, amid the roar of engines and dang of hammers, 
 where the strongest powers of nature are trained to work in the fairy 
 chains of art, how softly and fittingly falls upon iiie ear ttie accent of 
 science, the friend of that art, and the guide of that industry ! Here 
 where Priestley analysed the air, and Watt obtained the mastery over 
 steam, it well becomes the students of nature to gather round the stand- 
 ard which they carried so far into the fields of knowledge. And when on 
 other occasions we meet in quiet colleges and academic halls, how gladly 
 welcome is the union of fresh discoveries and new inventions with the 
 solid and venerable truths which are there treasured and taught. Long 
 may such union last ; the fair alliance of cultivated thought and practical 
 skill ; for by it labour is dignifiec' and science fertilised, and the condition 
 of human society exalted.* These were the words of a man who, while 
 earnest in the pursuit of science, was full of broad and kindly sympathy for 
 his fellow men, and of hopeful confidence in the future. We have but to 
 turn to the twenty Bioports of this Association, issued since 1865, to see 
 the realisation of that union of science and art to w'"icli he so confidently 
 
 looked forward, and to appijci^iate. the stupendous results which it has 
 
 • ■ ■=*,,'"• » » '• - J J , • k 
 
 ,' ' • I » . • 1 J , A 
 
 /TF^ 
 
 > ' -' 
 
p3 2 KEPORT— 1886. 
 
 acliicvcd. In one department alone — that to which my predecessor in this 
 chair so eloquently adverted in Aberdeen, the department of education in 
 science — how much has been accomplished since 1865. Phillips himself 
 lived to see a great revolution in this respect at Oxford. But no one in 
 1865 could have anticipated that immense development of local schools of 
 science of which your own Mason College and your admirable technical, 
 industrial, and art schools are eminent examples. Based on the general 
 education given by the new system of Board schools, with which the 
 name of the late W. E. Forster will ever be honourably connected, and 
 extending its influence upward to special training and to the highest 
 university examinations, this new scientific culture is opening paths of 
 honourable ambition to the men and women of England scarcely dreamed of 
 in 1865. I sympathise with the earnest appeal of Sir Lyon Playf-^^r, in his 
 Aberdeen address, in favour of scientific education ; but visiting England 
 at rare intervals, I am naturally more impressed with the progress that 
 has been made than with the vexatious delays which have occurred, and am 
 perhaps better able to appreciate the vast strides that have been taken 
 in the direction of that complete and all-pervading culture in science 
 which he has so ably advocated. 
 
 No one could have anticipated twenty years ago that a Birmingham 
 manufacturer, in whose youthfal days there were no schools of science 
 for the people, was about to endow a college, not only worthy of 
 this great city, but one of its brightest ornaments.' Nor could any- 
 one have foreseen the great development of local scientific societies, like 
 your Midland Institute and Philosophical Society, which are now 
 flourishing in every large town and in many of those of less magnitude. 
 The period of twenty-one years that has elapsed since the last Birming- 
 . ham meeting has also been an era of public museums and laboratories 
 ; for the teaching of science, from the magnificent national institutions at 
 South Kensington and those of the great universities and their colleges 
 down to tbose of the schools and field clubs in country towns. It has besides 
 been an era of gigantic progress in original work and in publication, 
 —a progress so rapid that workers in every branch of study have been 
 reluctantly obliged to narrow in more and more their range of reading and 
 of effort' to keep abreast of the advance in their several departments. 
 Lastly these twenty-one years have been characterised as the * coming of 
 age ' of that great system of philosophy with which the names of three 
 Englishmen, Darwin, Spencer, and Wallace, are associated as it founders. 
 Whatever opinions one may entertain as to the sufiiciency and finality of 
 this philosophy there can be no question as to its influence on scientific 
 thought. On the one hand it is inaccurate to compare it with so entirely 
 different things as the discovery of the chemical elements and of the law 
 of gravitation ; on the other, it is scarcely fair to characterise it as a 
 
 ■ It was in 1865 that Sir Josiah Mason was, c[uie,tly and without any public note, 
 beginning to lay tlie foundation of &is oFp'^ejna'ge-at Erdington. 
 
ADDRESS. 3 
 
 mere ' confused development ' of the mind of the age. It is indeed a new 
 attempt of science in its maturor years to grapple with those mysterious 
 questions of origins which occupied it in the days of its infancy, and 
 it is to be hoped that it may not, like the Titans of ancient fable, be 
 hurled back from heaven, or like the first mother find the knowledge 
 to which it aspires a bitter thing. In any case we should fully under- 
 stand the respon.oibility which we incui when in these times of full-grown 
 science wo venture to deal with tho g^eat problem of origins, and should 
 be prepared to find that in this field the new philosophy, like those which 
 have preceded it, may meet with very imperfect success. The agita- 
 tion of these subjects has already brought science into close relations, 
 sometimes friendly, sometimes hostile, it is to be hoped in the end help- 
 ful, with those great and awful questions of the ultimate destiny of 
 humanity, and its relations to its Creator, which must always be nearer to 
 the human heart than any of the achievements of science on its own 
 ground. In entering on such questions we should proceed with caution 
 and reverence, feeling that we are on holy ground, and that though, like 
 Moses of old, we may be armed with all the learning of our time, we are in 
 the presence of that which while it burns is not consumed ; of a mystery 
 which neither observation, experiment, nor induction can ever fully solve. 
 In a recent address, the late President of the Royal Society called 
 attention to the fact that within the lifetime of the older men of sc? .nee 
 of the present day, the greater part of the vast body of knowledge 
 included in the modern sciences of physics, chemistry, biology and 
 geology, has been accumulated, and the most important advances 
 made in its application to such common and familiar things as the rail- 
 way, ocean navigation, the electric telegraph, electric lighting, tho tele- 
 phone, the germ theory of disease, the use of anassthetics, the processes 
 of metallurgy, and the dyeing of fabrics. Even since the last meeting 
 in this city, much of this great work has been done, and has led to 
 general results of the most marvellous kind. What at that time could 
 have appeared more chimerical than the opening up by the enterprise of 
 one British colony of a shorter road to the East by way of the extreme 
 west, realising what was happily called by Milton and Cheadle *the 
 new North-west Passage,' making Japan the next neighbour of Canada 
 on the west, and offering to Britain a new way to her Eastern posses- 
 sions ; or than the possibility of this Association holding a successful meeting 
 on the other side of the Atlantic ? If I had ventured to prodict such 
 things in 1865, I should have appeared quite as visionary as if I were 
 now to ask you to meet in Australia or India, and to proceed thither by 
 the Canadian Pacific Railway and its new lines of steamer?, returning by 
 the Suez Canal.* Yet to-day this is quite as feasible as the Canadian 
 
 • It is expected that, on the completion of the whole of the connections of the 
 Canadian Pacific Railway, the time from ocean to ocean may be reduced to 116 hours, 
 and from London to Hong Kong to twenty-seven days. 
 
 a2 
 
4' REPORT — 1886. 
 
 visit would have been in 1865. It is science that has thus brought the onco 
 •widely separated parts of the world nearer to each other, and is breaking 
 down those gebgraphicd barriers which have separated the diflferent por- 
 tions of our widely extended British race. Its work in this is not yet 
 complete. Its goal to-day is its starting-point to-morrow. It is as far 
 as at any previous time from seeing the limit of its conquests, and every 
 victory gained is but the opening of the way for a farther advance. 
 
 By its visit to Canada the British Association has asserted its imperial 
 charactei*, and has consolidated the scientific interests of Her Majesty's 
 dominions, in advance of that great gathering of the industrial products 
 of all parts of the empire now on exhibition in London, and in advance of 
 ary political plans of Imperial federation.* There has even been a project 
 before us for an international scientific convention, in which the great 
 English republic of America shall take part, a project the realisation of 
 ■which -was to some extent anticipated in the fusion of the members of the 
 British and American Associations at Montreal and Philadelphia in 1884. 
 As a Canadian, as a past President of the American Association, and now 
 honoured with the Presidency of this Association, I may be held to repre- 
 sent in my own person this scientific union of the British Islands, of 
 the various Colonies and of the great Eepublic, which, whatever the 
 difficulties attending its formal accomplishment at present, is certain to 
 lead to an actual and real union for scientific work. In further- 
 ance of this I am glad to see here to-day influential representatives 
 of most of the British Colonies, of India, and of the Cnited States. 
 We welcome here also delegates from other countries, and though the 
 barrier of language may at present prevent a larger unicra, we may enter- 
 tain the hope that Britain, America, India, and the Colonies, working 
 together in the interest of science, may ultir lately render our English 
 tongue the most general vehicle of scientific thought and discovery, a 
 consummation of which I think there are, at present, many indications. 
 
 But, while science marches on from victory to victory, its path is 
 marked by the resting-places, of those who have fought its battles and 
 assured its advance. In looking back to 1865 there rise before me the 
 once familiar countenances of Phillips, Murchison, Lyell, Forbes, Jeflfreys, 
 Jukes, Rolleston, Miller, Spottiswoode, Fairbairn, Gassiot, Jarpenter, and 
 a host of others, present in full vigour at that meeting, but no more with 
 us. These were veterans of science ; but, alas ! many then young and 
 rising in fame are also numbered with the dead. It may be that before 
 another Birmingham meeting many of us, the older members now, will 
 also have passed away. But these men have left behind them ineffaceable 
 monuments of their work, in which they still survive, and we rejoice to 
 believe that, though dead to us, they live in that company of the great and 
 
 ' I should note here, in connection with this, the valuable volume of Canadian 
 Economics, edited by Mr. D. A. P. Watt, which was one of the results of the Montreal 
 meeting. 
 
ADDRESS. * 5 
 
 good of all ages who have entered into that nnsoen universe where all 
 that is high and holy and beautiful must go on accumulating till the timo 
 of the restitution of all things. Let us follow their example and carry 
 on their work, as God may give us power and opportunity, gathering- in 
 precious stores of knowledge and of thought, in the belief that all truth 
 is immortal, and must go on for ever bestowing blessings on mankind. 
 Thus will the memory of the mighty dead remain to us as a power 
 which — 
 
 Like a star 
 Beacons from the abode where the eternal are. 
 
 I do not wish, however, to occupy your time longer with general or 
 personal matters, but rather to take the opportunity afforded by this 
 address to invite your attention to some topics of scientific interest. In 
 attempting to do this I must have before me the warning conrojed by Pro- 
 fessor Huxley, in the address to which I have already referred, that in our 
 time science, like Tarpeia, may be crushed with the weight of the rewards 
 bestowed on her. In other words, it is impossible for any man to keep 
 pace with the progresi: of more than one limited branch of science, an'd 
 it is equally impossible to find an audience of scientific men of whom 
 anything more than a mere fraction can be expected to take an interest 
 in any one subject. There is, however, some consolation in the know- 
 ledge that a speaker who'is sufficiently simple for those who are advanced 
 specialists in other departments, will of necessity be also sufficiently simple 
 to be understood by the general public who are specialists in nothing. 
 On this principle a geologist of tue old School, accustomed to a great variety 
 of work, may hope so to scatter his fire as to reach the greater part of the 
 audience. In endeavouring to secure this end, I hav3 sought inspiration 
 from that ocean which connedts rather than separates Britain and America, 
 and may almost be said to be an English sea — the North Atlantic. The 
 geological history of this depression of the earth's crust, and its relation 
 to the continental masses which liirit it, may furnish a theme at once 
 generally intelligible and connected with great questions as to the struc- 
 ture and history of the earth, which have excited the attention alike of 
 physicists, geologists, biologists, geographers and ethnologists. Should 
 I, in treating of these questions, appear to be somewhat abrupt and 
 dogmatic, and to indicate rather than state the evidence of the general 
 views announced, I trust you will kindly attribute this to the exigeucies 
 of a short address. 
 
 If we imagine an observer comtemplating the earth from a convenient 
 distance in space, and scrutinising its features as it rolls before him, we 
 may suppose him to be struck with the fact that eleven-sixteenths of its 
 surface are covered with water, and that the land is so unequally dis- 
 tributed that from one point of view b > would see a hemisphere almost 
 exclusively oceanic, while nearly the whole of the dry land is gathered in 
 the opposite hemisphere. He might observe that the great oceanic area 
 
• REPORT — 1886. 
 
 of the Pacific and Antarctic Oceana is dotted with islands — like a shallow 
 pool with stones rising above its surface — as if its general depth were 
 tmall in comparison with its area. Ho might also notice that a mass or 
 belt of land surrounds each polo, and that the northern ring sends olF 
 to the southward three vast tongues of land and of mountain chains, 
 terminating respectively in South America, South Africa, and Australia, 
 towards which feebler and insular processes are given off by the Ant. 
 arctic continental mass. This, as some geographers have observed,' 
 gives a rudely three-ribbed aspect to the earth, though two of the three 
 ribs are crowded together and form the Europ-asian mass or double con- 
 tinent, while the third is isolated in the single continent of America. Ho 
 might also observe that the northern girdle is cut across, so that the 
 Atlantic opens by a wide space into the Arctic Sea, while the Pacific is 
 contracted toward the north, but confluent with the Antarctic Ocean. The 
 Atlantic is also relatively deeper and less cumbered with islands than tha 
 Pacific, which has the higher ridges near its shores, constituting what 
 some visitors to the Pacific coast of America have not inaptly called the 
 * back of the world,' while the wider slopes face the narrower ocean, into 
 which for this reason the greater pt rt of the drainage of the land is 
 poured.^ The Pacific and Atlantic, though both depressions or flattenings 
 of the earth, are, as we shall find, different in age, character, and conditions ; 
 and the Atlantic, though the smaller, is the older, and from the geological 
 point of view, in some respects, the more important of the two. 
 
 If our imaginary observer had the means of knowing anything of the 
 rock formations of the continents, he would notice tuat those bounding 
 the North Atlantic are in general of great age, some belonging to the 
 Laurentian system. On the other hand, he would see that many of the 
 mountain ranges along the Pacific are comparatively new, and that 
 modern igneous action occurs in connection with them. Thus he might 
 be led to believe that the Atlantic, though comparatively narrow, is an 
 older feature of the earth's surface, while the Pacific belongs to more 
 modern times. But he would note in connection with this that the oldest 
 rocks of the great continental masses are mostly tov/ard their northern 
 ends, and that the borders of the northern ring of land and certain ridges 
 extending southwards from it constitute the most ancient and permanent 
 elevations of the earth's crust, though now greatly surpassed by moun- 
 tains of more recent age nearer the equator. Before leaving this general 
 survey we may make one further remark. An observer looking at the 
 earth from without would notice that the margins of the Atlantic and 
 the main lines of direction of its mountain chains are north-east and 
 south-west, and north-west and south-cast, as if some early causes had 
 
 ' "Dana, Maniud of Geology, introductory part ; Green, Vestiges of a Molten Globe 
 has summed up these facts. 
 
 * Mr. Mellard Reade, in two Presidential addresses before the Geological Society 
 of Liverpool, has well illustrated this point and its geological consequence. 
 
ADDRESS. 7 
 
 dotormined tho occuirenco of elevations along j^reat circles of the earth's 
 surface tfltignnt to the polar circles. 
 
 We are invited by the preceding general glance at the surface of the 
 earth to ask certain questions respecting the Atlantic. (1) "What has at 
 first determined its position and form ? (2) What changes has it experi- 
 encod in the lapse of geological time ? (S) What relations have these 
 changes borne to the ievelo'iment of life on the land and in the watc 
 (4) What is its probable future ? 
 
 Before attempting to answer these questions, which I shall not i -Ke 
 up formally in succession, but rather in connection with each other, it is 
 necessary to state as briefly as possible certain general conclusions re- 
 specting the interior of the earth. It is popularly supposed that we 
 know nothing of this beyond a superficial crust perhaps averaging 50,000 
 to 100,000 feet in thickness. It is true we have no means of exploration 
 in the earth's interior, but the conjoined labours of physicists and geo- 
 logists have now proceeded sufficiently far to throw much inferential 
 light on the subject, and to enable us to make some general affirmafciounj 
 with certainty ; and these it is the more necessary to state distinctly, 
 since they are often treated as mere subjects of speculation and fmitless 
 discussion. 
 
 (1) Since the dawn of geological science, it has been evident that the 
 crust on which we live must be supported on a plastic or partially liquid 
 mass of heated rock, approximately uniform in quality under the whole 
 of its area. This is a legitimate conclusion from the wide distrihution of 
 volcanic phenomena, and from the fact that the ejections of volcanoes, while 
 locally of various kinds, are similar in every part of the world. It led to 
 the old idea of a fluid interior of the earth, but this is now generally 
 abandoned, and this interior heated and plastic layer is regarded as 
 merely an under-crust. 
 
 (2) We have reason to believe, as the result of astronomical investiga- 
 tions,' that, notwithstanding the plasticity or liquidity of the under-crust, 
 the mass of the earth — its nucleus as we may call it — is practically solid 
 and of great density and hardness. Thus we have the apparent paradox 
 of a solid yet fluid earth; solid in its astronomical relations, liquid or 
 plastic for the purposes of volcanic action and superficial movements. ^ 
 
 (3) The plastic sub-crust is not in a state of dry igneous fusion, 
 but in that condition of aqueo-igneous or hydro- thermic fusion which 
 
 ' Hopkins, Mallet, Sir William Thomson, and Prof, G. H. Darwin maintain the 
 solidity and rigidity of the earth on astronomical grounds ; but different conclusions 
 have been reached by Hennesey, Delaunay, and Airy. In America Barnard and . 
 Crosby, Button, Le Conte, and Wadsworth have discussed these questions. 
 
 * An objection has been taken to the effect that the supposed ellipsoidal form of 
 tlie equator is inconsistent with a plastic sub-crust. But this ellipsoidal form is not 
 absolutely certain, or, if it exists, is very minute. Bonney has in a recent lecture 
 suggested the important consideration that a mass may be slowly mobile under long 
 continued pressure, while yet rigid with reference to more sudden movements 
 
8 REPOHT — 1886. 
 
 arises from tho action of heat on moist suhstances, and which mcy either 
 bo regarded as a fusion or as a species of solution at a very high tempera- 
 ture. This we learn from tho phenomena of volcanic action, and from 
 the composition of the volcanic and plutonic rocks, as well as from such 
 chemical experiments as those of Danbree and of Tilden and Shenstone.' 
 (4) The interior sub-cmst is not perfectly homogeneous, but may be 
 roughly divided into two layers or magmas, as they have been called : an 
 upper, highly silicious or acidic, of ' <w specific gravity and light coloured, 
 and corresponding to such kinds of >Tutonic and volcanic rocks as granite 
 and trachyte ; and a lower, less silicious or more basic, more dense, and 
 more highly charged with iron, and corresponding to such igneous rocks 
 as t)ie dolorites, basalts, and kindred lavas. It is interesting here to 
 note that this conclusion, elaborated by Durocher and von Walters- 
 hausen, and usually connected with their names, appears to have been 
 first announced by John Phillips, in his ' Geological Manual,' and as a mere 
 common sense deduction from the observed phenomena of volcanic action 
 and the probable results of the gradual cooling of the earth.'* it receives 
 striking conformation from the observed succession of acidic and basic 
 volcanic rocks of all geological periods and in all localities. It would 
 even seem, from recent spectroscopic investigations of Lockyer, that there 
 is evidence of a similar succession of magmao in the heavenly bodies, and 
 the discovery by Nordenskiold of native iron in Greenland basalts, 
 affords a probability that the inner magma is in part metallic.^ 
 
 (5) Where rents or fissures form in the upper crust, the material of 
 the lower crust is forced upward by the pressure of the less supported 
 portions of the former, giving rise to volcanic phenomena either of an 
 explosive or quiet character, as may be determined by contact with water. 
 The underlying material may also be carried to the surface by the agency 
 of heated water, producing those quiet discharges which Hunt has 
 
 > Phil. Trans. 1884. Also Crosby in Proc. Boston Soc. Nat. Hist. 1883. 
 
 * rhillips say3 (Manval of Geoloyj, 1855, p. 493): 'If we regard them (the 
 internal crystalline rocks) as acquiring solidification by cooling in zones parallel to 
 the surface, we should have sheets of granitic and basaltic rocks generated below 
 the first uppermost, the last undermost, while above the several strata were produced 
 in a series beginning at the bottom. In this sense the rocks of fusion may be called 
 with Lyell hypogetie. Certainly under particular areas of country are found t lence 
 of the liquefaction of one set of igneous products after the solidification of others. 
 Many dykes of basalt traversing granite show tliemselves to have been in fusion after 
 the solidification of the granite.' In various forms Phillips returns to this idea, as at 
 pp. 5r)6 and 564, in that unpretending manner which was his wont. Dr. Sterry Hunt 
 has kindly 'directed my attention to the fact of Phillips' right of priority in this 
 matter. Durocher in 1857 elaborated the theory of magmas in the Annates des Mines, 
 and we are indebted to Dutton, of the United States Geological iSurvey, for its 
 detailed application to the remarkable volcanic outflows of Western America. 
 
 ' These basalts occur at Ovifak, Greenland. Andrews has found small particles 
 of iron in British basalts. Prestwich and Judd have referred to the bearing on 
 general* geology of these facts, and of Lockyer's suggestions. 
 
ADDRESS. 9 
 
 named crenitic. It is to be observed here that explosive volcanic pheno- 
 mena, and the formation of cones, are, as Prestwich has well remarked, 
 characteristic of an old and thickened crust ; quiet ejection from fissures 
 and hydro-thermal action may have been more common in earlier periods 
 and with a thinner over-crust. 
 
 (6) The contraction of the earth's interior by cooling and by the 
 emission of material from below the over-crust, has caused this crust to 
 press downward, and therefore laterally, and so to effect great bends, folds, 
 and plications ; and these modified subsequently by surface denudation 
 constitute mountain chains and continental plateaus. As Hall long ago 
 pointed out,' such lines of folding have boon produced more especially 
 whore thick sediments had been laid down on the sea ^^ )ttom. Thus we 
 have hero another apparent parodox, namely, that the elevations of the 
 earth's crust occur in the places where tbi greatest burden of detritus 
 has been laid down upon it, and where consequently the crust has been 
 soft'ined and depressed. We must beware, in this connection, of exagge- 
 rated notions of the extent of contraction and of crumpling required to form 
 mountains. Bonney has well shown, in lectures delivered at the London 
 Institution, that an amount of contraction, almost inappreciable in com- 
 parison with the diameter of the earth, would be sufficient ; and that as the 
 greatpst mountain chains are less than ^rJ^th of the earth's radius in 
 hei Vey would on an artificial globe a foot in diameter be no more 
 impo. ^nt than the slight inequalities that might result from the papar 
 gores overlapping each other at the edges. 
 
 (7) The crushing and sliding of the over-crust implied in these move- 
 ments raise some serious questions of a physical character. One of these 
 relates to the rapidity or slowness of such movements, and the consequent 
 degree of intensity of the heat developed, as a possible cause of meta- 
 morphism of rocks. Another has reference to the possibility of changes 
 in the equilibrium of the earth itself as resultii^g from local collapse and 
 ridging. These questions in connection with the present dissociation of 
 the axis of rotation from the magnetic poles, and with changes of climate, 
 have attracted some attention,^ and probably deserve further considera- 
 tion on the part of physicists. In so far as geological evidence is con- 
 cerned, it would seem that the general association of crumpling with 
 metamorphism indicates a certain rapidity in the process of tiountain- 
 making, and consequent development of heat, and the arrangemei^t of the 
 older rocks around the Arctic basin forbids us from assuming any exten«ive 
 movement of the axis of rotation though it does not exclude changes to 
 a limited extent. I hope that Professor Darwin will discuss these points 
 in his address to the physical section. 
 
 ' Hall (American Association Address, 1857, subsequently republished, .-"ith 
 additions, as Contributions to the Geological History of the American Contineivt, 
 Mallet), Kogers, Dana, Le Conte, «&c. 
 
 ' See recent papers of Oldham and Fisher in Geological Magazine and Philo' 
 tophioal Magazine, July 1886. Also Peroche, lievol. Polaires. Paris, 1886. 
 
 a5 
 
10 EEPORT — 1886. 
 
 I wish to formulate these principles as distinctly as possible, and as 
 the result of all the long series of observations, calcalations, and discus- 
 sions since the time of Werner and Hutton, and in which a vast number 
 of able physicists and naturalists have borne a part, because they may be 
 considered as certain deductions from our actual knowledge, and because 
 they lie at the foundation of a rational physical geology. 
 
 We may popularise these deductions by comparing the earth to a 
 ('rupe or stone-fruit, such as a plum or peach, somewhat dried up. It has 
 a large and intensely hard stone and kernel, a thin pulp made up of two 
 layers, an inner more dense and dark coloured, and an outer less dense 
 and lighter coloured. These constitute the under-crust. On the outside 
 it has a thin membrane or over-crust. In the process of drying it has 
 slightly shrunk, so as to produce ridges and hollows of the outer crust, 
 and this outer crust has cracked in some places, allowing portions bf the 
 pulp to ooze out — in some of these its lower dark substance, in others its 
 upper and lighter material. The analogy extends no farther, for there is 
 nothing in our withered fruit to represent the oceans occupying the lower 
 parts of the surface or the deposits which they have laid down. 
 
 Keeping in view these general conclusions, let us now turn to their 
 bearing on the origin and history of the North Atlantic. 
 
 Though the Atlantic is a deep ocean, its basin does not. constitute so 
 much a depression of the crust of the earth as a flattening of it, and this, 
 as recent soundings have shown, with a slight ridge or elevation along its 
 middle, and banks or terraces fringing the edges, so that its form is not 
 so much that of a basin as that of a shallow plate with its middle a little 
 raised. Its true permanent margins are composed of portions of the over- 
 crust folded, ridged up and crushed, as if by lateral pressure emanating 
 from the sea itself. We cannot, for examiple, look at a geological map of 
 America without perceiving that the Appalachian ridges, which intervene 
 between the Atlantic and the St. Lawrence valley, have been driven 
 bodily back by a force acting from the east, and that they have resisted 
 this pressure only where, as in the Gulf of St. Lawrence and the Catskill 
 region of New York, they have been protected by outlying masses of very 
 old rocks, as, for example, by that of the island of Newfoundland and that 
 of the Adirondack Mountains. ■ The admirable work begun by my friend 
 and fellow student Professor James Nicol, followed up by Hicks, Lap- 
 worfch, and others, and now, after long controversy, fully confirmed by the 
 recent observations of the geological survey of Scotland, has shown the 
 most intense action of the same kind on the east side of the ocean in the 
 Scottish highlands; and the more widely distributed Eozoic rocks of Scan, 
 dinavia may be appealed to in further evidence of this.* 
 
 If we now inquire as to the cause of the Atlantic depression, we must 
 
 ■ Address to the Geological Section, by Prof. Judd, Aberdeen Meeting, 1885. 
 According to Rogers, the Crumpling of the Appalachians has reduced a breadth of 
 158 miles to about 60. 
 
ADDRESS. 1 1 
 
 go back to a time when tho areas now occupied by the Atlantic and 
 its bounding coasts were parts of a shoreless sea in which tho earliest 
 gneisses or stratified granites of the Laurentian age were being laid 
 down in vastly ertended beds. These ancient crystalline rocks have been 
 the subject of much discussion and controversy, and as they constitute 
 the lowest and probably the firmest pai*t of the Atlantic sea-bed, it is 
 necessary to inquire as to their origin and history. Dr. Bonney, the 
 late President of the Geological Society, in his Anniversary address, and 
 Dr. Sterry Hunt, in an elaborate paper communicated to the Royal 
 Society of Canada, have ably summed np the hypotheses as to the origin 
 of the oldest Laurentian beds. At the basis of these hypotheses lies the 
 admission that the immensely thick beds of orthoclase gneiss, whicl are 
 the oldest stratified rocks known to us, are substantiaMy the same in 
 composition with the upper or silicious magma or layer of the under- 
 crust. They are, in short, its materials either in their primitive condition 
 or merely rearranged. One theory considers them as original products 
 of cooling, owing their lamination merely to the succepaive stages of the 
 process. Another view refers them to the waste and rearrangement of 
 the materials of a previously massive granite. Still another holds that all 
 our granites really arise from the fusion of old guv^isses of originally 
 aqueous origin, while a fourth refers the gneisses themselves to molecular 
 changes efiected in granite by pressure. These several views, in so far as 
 they relate to the oldest or fundamental Laurentian gneiss, may be 
 arranged under the following heads: (1) Endoplutonic, or thait which 
 regards all the old gneisses as molten rocks cooled from without inward 
 in successive layers.' (2) Exoplatonic, or that which considers tt.em as 
 made up of matter ejected from below the upper crust in the manner of 
 volcanic action,'* (3) MetamorpMc, which supposes the eld gneisses to 
 arise from the crystallisation of detrital matter spread over the sea-bottom, 
 and either igneous or derived from the decay of igneous rocks.' (4) 
 Chaotic or Thermo-chaotic, or the theory of deposit from the turbid waters 
 of a primeval ocean either with or without the aid of heat. In one form 
 this was the old theory of Werner.'' (5) Granitic or Hydro-thermic, which 
 supposes the action of heated waters penetrating below the crust to be 
 constantly bringing up to the surface raineral matters in solution and 
 depositing these so as to form felspathic and other rocks.^ 
 
 ' Naumann, Phillips, Durocher, McFarlane, &c. 
 
 ' Clarence King, Tornebohm. Marr, &c. 
 
 ■ Lyell, Kopp, Reusch, Judd, &c. 
 
 * Scrope, Delabeche, Daubr6e. 
 
 » Hunt, loo. oit. The following is Dr. Hunt's summary statement of this theory : 
 * The globe consolidating at the centre left, it is conceived, a superficial layer of basic 
 silicates, which has yielded all the fixed elements of the earth's crust. This' layer 
 formed the first land and the floor of the primeval sea, the acid watsrs ofl Ti^hich, 
 permeating and partially decomposing it, becama thereby chemically neutralised 
 This last-cooled layer, mechanic^y disintegrated, saturated with water, and heated 
 
 A6 
 
12 REPORT— 1886. 
 
 It will be observed, in regard to these theories, that none of them 
 
 Bnpposes that the old gneiss is an ordinary sediment, but that all regard 
 
 it as formed in excepLlonal circumstances, these circumstances being the 
 
 absence of land and of sub-aerial decay of rock> and the presence wholly or 
 
 principally of the material of the upper surface of the recently hardened 
 
 crust. This being granted, the question arises. Ought we not to combine 
 
 these several theories and to believe that the cooling crust has hardened 
 
 in successive layers from without inward ; that at the same time fissures 
 
 were locally discharging igneous matter to the surface ; that matter held 
 
 in suspension in the ocean and matter held in solution by heated waters 
 
 rising from beneath the outer crust were mingling their materials in the 
 
 deposits of the primitive ocean ? It would seem that the combination of 
 
 all these agencies may safely be invoked ag causes of the pre-Atlantio 
 
 deposits. This is the eclectic position which I endeavoured to maintain 
 
 in my address before the Minneapolis Meeting of the American Association 
 
 in 1883, and which I still hold to be in every way probable. 
 
 A word here as to metamorphism, a theory which, like many others, has 
 been first ruu to death and then discredited, but which to the moderate de- 
 gree in which it was originally held by Lyell is still valid. Nothing can be 
 more certain than that the composition of the Laurentian gneisses forbids 
 us to suppose that they can be ordinary sediments metamorphosed. They 
 are rocks peculiar in their origin, and not parallelled unless exceptionally 
 in later times. On the other hand, they have undoubtedly experienced 
 very imnortant changes, more especially as to crystallisation, the state of 
 combii .ition of their ingredients, and the development of disseminated 
 minerals ; ^ and while this may in part be attributed to the mechanical 
 pressure to which they have been subjected, it requires also the action of 
 hydrothermic agencies. Any theory which fails to invoke both of these 
 kinds of force must necessarily be partial and imperfect. 
 
 by the central mass, was the source of mineral springs, holding in solution the silicates 
 which built up the ancient gn 3isses and similar rocks. Granitic veins and zeolites 
 are due to survivals of the pre jess which generated the gneissic rocks. The hypo- 
 thesis of their formation from materials brought to the surface by mineral springs 
 foom the primitive basic layrr affords, it is claimed, the elements of a complete and 
 intelligible explanation of the origin of the Eozoic rocks. This upward lixiviation of 
 the primitive mass, and the c eposition over it of an acidic granite- like rock, would 
 leave below a highly basic material, and the division of the mass thus established 
 would correspond to that of th<3 trachytic and doleritic magmas, which have been 
 conjectured to be the sources of two great tj-^pes of eruptive rocks. Inasmuch, how- 
 ever, as according to the present hypothesis these two layers of basic and acidic 
 matters are the results of aqueous action, and not of an original separation in a 
 plutonic mass, as imagined by Phillips and Durocher, their composition would be 
 subject to many local variations.' 
 
 • The first of these is what Bonney has called Metastasis. The second and third 
 come under the name Metacrasis. Methylosis, or change of substance, is altogether 
 exceptional, and not to be credited except on the best evidence, or in cases where 
 volatile matters have been expelled, as in the change of Hematite into Magnetite, or 
 of bituminous coal into anthracite. 
 
ADDRESS. 13 
 
 Bat all metamorphio rock8 are not of the same chai'acter with the 
 gneisses of the Lower Laurentian. Even in the Middle and Upper Lau- 
 rentian we have metamorj-nio rocks, e.g. quartzite and limestone, which 
 mnst originally have bean ordinary aqueons deposits. Still more in 
 the succeeding Huronim and its associated series of beds, and in the 
 Lower Palaeozoic, local raefcamorphic change has been undergone by rocks 
 quite similar to thosj which i their unaltered state constitute regular 
 sedimentary deposits In the case of these later rocks it is to be borne 
 in mind that, while f ome may have been of volcan' • origin, others may 
 have been sediments rich in undecomposed fragmen , of silicates. It is 
 a mistake to suppose that the ordinary decay of stratified silicious rocks 
 is a process of kaolinisation so perfect as to eliminate all alkaline matters. 
 On the contrary, the fact, which Judd has recently well illustrated in the 
 case of the mud of the Nile, applies to a great number of similar deposits 
 in all parts of the world, and shows that the finest sediments have not 
 usually been so completely lixiviated as to be destitute of the basic matters 
 necessary for their conversion into gneiss, mica-schist, and similar rocks 
 when the necessary agencies of metamorphism are applied to them, and 
 this quite independently of any extraneous matters introduced into them 
 by water or otherwise. Still it must be steadily kept in view that many 
 of the old pre-Cambrian crystalline rocks must have been different 
 originally from those succeeding them, and that v^onsequently these last 
 even when metamorphosed present different characters. 
 
 I may remark here that, though a paleeontologist rather than a 
 lithologist, it gives me great pleasure to find so much attention now given 
 in this country to the old crystalline rocks, and to their study micro- 
 scopically and chemically as well as in the field, a work in which Sorby 
 and Allport were pioneers. As a pupil of the late Professor Jameson, 
 of Edinburgh, my own attention was early attracted to the study of 
 minerals and rocks as the stable foundations of geological science ; and 
 as far back as 1841 I had learnt of the late Mr. Sanderson, of Edinburgh, 
 who worked at Nicol's sections, how to slice rocks and fossils ; and since 
 that time I have been in the habit of examining everything with the 
 microscope. The modem developments in this direction are therefore 
 very gratifying, even though, as is naoural, they may sometimes appear 
 to be pushed too far or their value over-estimated. 
 
 That these old gneisses were deposited not only in what is now the 
 bed of the Atlantic, but also on the great continental areas of America 
 an'I Europe, anyone who considers the wide extent of these rocks repre- 
 sented on the map recently published by Professor Hull can readily under- 
 stand.' It is true that Hull supposes that the basin of the Atlantic 
 itself may have been land at this time, but there is no evidence of this, 
 more especially as the material of the gneiss could not have been detritus 
 derived from sub-aerial decay of rock. 
 
 ' Trans. Royal Imh Academy. 
 
14 REPORT— 1886. 
 
 Let us suppose, then, the floor of old ocean covered with a flat pave- 
 ment of gneiss, or of that material which is now gneiss, the next question 
 is how and when did this original bed become converted into sea and 
 land. Here we have some things certain, others most debatable. That 
 the cooling mass, especially if it was sending out volumes of softened 
 rocky ijaaterial, either in the exoplutonic or in the crenitic way, and piling 
 this on the surface, must soon become too small for its shell, is apparent ; 
 but when and where would the collapse, crushing, and wrinkling inevit- 
 able from this cause begin ? Where they did begin is indicated by the 
 lines of mountain-chains which traverse the Laurentian districts ; but the 
 reason why is less apparent. The more or less unequal cooling, harden- 
 ing and conductive power of the outer crust we may readily assume. 
 The driftage unequally of water-borne detritus to the south-west by the 
 bottom currents of the sea is another cause, and, as we shall soon see, most 
 efiective. Still another is the greater cooling and hardening of the crust 
 in the polar regions, and the tendency to collapse of the equatorial pro- 
 tuberance from the slackening of the earth's rotation. Besides these the 
 internal tides of the earth's substance at the times of solstice would exert 
 an oblique pulling force on the crust, which might tend to crack it along 
 diagonal lines. From whichever of these causes or the combination of the 
 whole, we know that within the Laurentian time folded portions of the 
 earth's crust began to rise above the general surface in broad belts running 
 from N.E. to S.W., and from N.W. to S,E., where the older mountains 
 of Eastern America and Western Europe now stand, and that the subsi- 
 dence of the oceanic areas allowed by this crumpling of the crust permitted 
 other areas on both sides of what is now the Atlantic to form limited 
 tablelands.' This was the beginning of a process repeated again and again 
 in subsequent times, and which began in the Middle Laurentian, when for 
 the first time we find beds of quartzite, limestone, and iron ore, and 
 graphitic beds, indicating that there was already land and water, and 
 that the sea, and perhaps the land, swarmed with animal and plant life 
 of forms unknown to us for the most part now. Independently of the 
 questions as to the animal nature of Eozoon, I hold thau we know, as 
 certainly as we can know anything inferentially, the existence of these 
 primitive forms of life. If I were to conjecture what were the early 
 forms of plant and animal life, I would suppose that just as in the 
 Pal03ozoic the acrogens culminated in gigantic and complex forest trees, 
 so in the Laurentian the algee, the lichens, and the iiiosses grew to 
 dimensions and assumed complexity of structure unexampled in later 
 times, and that in the sea the humbler forms of Protozoa and Hydrozoa 
 were the dominant types, but in gigantic and complex forms. The land 
 of this period was probably limited, for the moat part, to high latitudes, 
 
 ' Daubr^e's curious experiments on the contraction of caoutchouc balloons, partially 
 harujned by coating with varnish, shows how small inequalities of the crust, from 
 whatever cause arising, might affect the formation of wrinkles, and also that trans- 
 verse as well as longitudinal wrinkling might occur. 
 
ADDRESS. IS 
 
 and its aspect, though more ragged and abrupt, and of greater elevatioij, 
 must have been of that character which we still see in the Lauren- 
 tian hills. The distribution of this ancient land is indicated by the 
 long lines of old Lanrentian rock e^:tending from the Labrador coast 
 and the north shore of the St. Lawrence, and along the eastern slopes of 
 the Appalachians in Ameiica, and the like rocks of the Hebrides, the 
 Western Highlands, and the Scandinavian mountains. A small but in- 
 teresting remnant is that in the Malvern Hille, so well described by HoU. 
 It will be well to note here and to fix on our minds that thes'^ ancient 
 ridges of Eastern America and Western Europe have been greatly denuded 
 and wasted since Lanrentian times, a7id that it is along their eastern 
 sides that the greatest sedimentary accumulations have been deposited. 
 
 From this time dates the introduction of that dominance of existing 
 causes which forms the basis of uniformitarianism in geology, and which 
 had to go on with various and great modifications of detail, through the 
 successive stages of the geological history, till the land and water of the 
 northern hemisphere attained to their present complex structure. 
 
 So soon as we have a circumpolar belt or patches of Eozoic ' land and 
 ridges running southward from it, we enter on new and more complicated 
 methods of growth of the continents and seas. Here we are indebted to 
 Le Conie for clearly pointing out that our original Eozoic tracts of con- 
 tinent were in the earliest times areas of deposition, and that the first 
 elevations of land out of the primeval ocean must have differed in import- 
 ant points from all that have succeeded them ; but they were equally 
 amenable to the ordinary laws of denudation. Portions of these oldest 
 crystalline rocks, raised out of the protecting water, were now eroded by 
 atmospheric agents, and especially by the carbonic acid, then existing 
 in th© atmosphere perhaps more abundantly than at present, under 
 whose influence the hardest of the gneissic rocks gradually decay. The 
 Arctic lands weie subjected in addition to the powerful mechanical 
 force of frost and thaw. Thus every shower of rain and every swollen 
 stream would carry into the sea the products of the waste of land, sorting 
 them into fine clays and coarser sands ; and the cold currents which cling 
 to the ocean bottom, now determined in their courses, not merely by the 
 earth's rotation, but also by the lines of folding on both sides of the 
 Atlantic, would carry south-westward, and pile up in marginal banks of 
 great thickness, the debris produced from the rapid waste of the land 
 already existing in the Arctic regions. The Atlantic, opening widely to 
 the north, and having large rivers pouring into it, was especially the 
 ocean characterised, as time advanced, by the prevalence of these pheno- 
 mena. Thus throughout the geological history it has happened that, while 
 the middle of the Atlantic has received merely organic deposits of shells 
 of Foraminifera and similar organisms, and this probably only to a small 
 amount, its margins have had piled upon them beds of detritus of immense 
 
 ' Or Archaean, or pre-Cambrian, if these terms are preferred. 
 
M REPORT— 1886. 
 
 thickness. Professor Hall, of Albany, was the first geologist who pointed 
 out the vast cosmio in^portance of these deposits, and that the nionntaina 
 of both sides of the Atlantic owe their origin to these great lines of de- 
 position, along with the fact, afterwards more fully insisted on by Kogers, 
 that the portions of the cmst which received these masses of debri > became 
 thereby weighted down and softened, and were more liable than other 
 parts to lateral crushing.' 
 
 Thus in the later Eozoic and early Paleeozoic times, which succeeded 
 the first foldings of the oldest Laurentian, great ridges were thrown up, 
 along the edges of which were beds of limestone, and on their summits 
 and sides thick masses of ejected igneous rocks. In the bed of the central 
 Atlantic there are no such accumulations. It must have been a flat, 
 or slightly ridged, plate of the ancient gneiss, hard and resisting, though 
 perhaps with a few cracks, through which igneous matter welled up, as 
 in Iceland and the Azores in more modern times. In this condition of 
 things we have causes tending to perpetuate and extend the distinctions 
 of ocean and continent, mountain and plain, already begun ; and of these 
 we may more especially note the continued subsidence of the areas of 
 greatest marine deposition. This has long attracted attention, and afibrds 
 very convincing evidence of the connection of sedimentary deposit as a 
 cause with the subsidence of the crust.* 
 
 We are indebted to a French physicist M. Faye,^ for an important 
 suggestion on this subject. It is that the sediment accumulated along 
 the shores of the ocean presented an obstacle to radiation, and conse- 
 quently to cooling of the crust, while the ocean floor, unprotected and 
 unweighted, and constantly bathed with currents of cold water, having 
 great power of convection of heat, would be more rapidly cooled, and so 
 
 • The connection of accumulation with subsidence was always a familiar con- 
 sideration with geologists ; but Hall seems to have been the first to state its true 
 significance as a geological factor, and to see that those portions of the crust which 
 are weighted down by great detrital accumulations are necessarily those which, in 
 succeeding movements, were elevated into mountains. Other American geologists, 
 as Dana, Rogers, Hunt, Le Conte, Crosby, &c. have followed up Hall's primary sug- 
 gestion, and in England, Hicks, Fisher, Starkie Gardiner, Hull, and others, have 
 brought it under notice, and it enters into the great generalisations of Lyell on these 
 subjects. 
 
 » Dutton in Report of U.S. Geological Survey, 1881. From facts stated in this 
 report, and in my Acadian Geology, it is apparent that in the Western States and in the 
 coalfield of Nova Scotia shallow-water deposits have been laid down up to thicknesses 
 of 10,000 to 20,000 feet in connection with continuous subsidence. See also a paper 
 by Eicketts in the Geol. Mag. 1883. It may be well to add here that this doctrine 
 of the subsidence of wide areas being caused by deposition does not justify the con- 
 clusion of certain glacialists that snow and ice have exercised a like power in glacial 
 jjeriods. In truth, as will appear in the sequel, great accumulations of snow and ice 
 require to be preceded by subsidence, and wide continental areas can never be covered 
 with deep ^now, while of course ice can cause no addition of weight to submerged 
 areas. 
 
 ' Hevue Sdentifique, 1886. 
 
ADDRESS. 17 
 
 would become thicker and stronger. This suggestion is complementary 
 to the theory of professor Hall, that the areas of greatest deposit on tho 
 margins of the ocean are necessarily those of greatest folding and conse- 
 quent elevation. We have thus a hard, thick, resisting ocean bottom 
 which as it settles down toward the interior, under the influence of 
 gravity, squeezes upward and folds and plicates all the soft sediments 
 deposited on its edges. The Atlantic area is almost an unbroken cake of 
 this kind. The Pacific area has cracked in many places, allowing the 
 interior fluid matter to ooze out in volcanic cjectiong. 
 
 It may be said that all this supposes a permanent continuance of the 
 ocean basins, whereas many geologists postulate a mid-Atlantic continent * 
 to give the thick masses of detritus found in the older formations both in 
 Sastern America and Western Europe, and which thin off in pvoceeding 
 into the interior of both continents. I prefer with Hall to consider these 
 belts of sediment as in the main the deposits of northern currents, and de- 
 rived from Arctic land, and that like the great banks of the American coast 
 at the present day, which are being built up by the present Arctic current, 
 they had little to do with any direct drainage from th; adjacent shore. 
 We need not deny, however, that such ridges of land as existed along the 
 Atlantic margins were contributing their quota of river-borne material, 
 just as on a still greater scale the Amazon and Mississippi are doing now, 
 and this especially on the sides toward the present continental plateans, 
 though the greater part must have been derived from the wide tracts of 
 Laurentian land within the Arctic Circle or near to it. It is further 
 obvious that tbe ordinary reasoning respecting the necessity of continental 
 areas in the present ocean basins would actually oblige ns to suppose 
 that the whole of the oceans and continents had repeatedly changed 
 places. This consideration opposes enormous physical difi&culties to any 
 theory of alternations of the oceanic and continental areas, except locally 
 at their margins. I would, however, refer you for a more full discussion of 
 these points to the address to be delivered to-morrow by the President of 
 the Geological Section. 
 
 But the permanence of the Atlantic depression does not exclude the 
 idea of successive submergences of the continental plateaus and marginal 
 slopes, alternating with periods of elevation, when the ocean retreated 
 from the continents and contracted its limits. In this respect the Atlantic 
 
 > Among American geologists, Dana and Le Conte, though from somewhat differ- 
 ent premises, maintain continental permanence. Crosby has argued on the other 
 side. In Britain, Hull has elaborated the idea of interchange of oceanic and conti- 
 nental areas in his memoir in Tran$. Dublin Society, and in his work entitled The 
 Physical History of the British Islands. Godwin-Austin argues powerfully for the 
 permanence of the Atlantic basin, Q. J. Geol. Society, voL xii. p. 42. Mellard 
 Beade ably advocates the theory of mutation. The two views require, in my judg- 
 ment, to be combined. More especially it is necessary to take into the account the 
 existence of an Atlantic ridge of Laurentian rock on the west side of Europe, of 
 which the Hebrides and the oldest rocks of Wales, Ireland, Western France, and 
 Portugal are remnants. 
 
 A 9 
 
18 REPoni— 1886. 
 
 of to-day is much smaller than it was in those times «7hen it spread 
 widely over the continental plains and slopr ., and much larger than it 
 has been in times of continental elevation. This leads us to the further 
 conaideration that, while the ocean beds have been sinking, other areas have 
 teen better snpp jrted, and constitute the continental plateaus ; and that 
 it has been at or near the junctions of these sinking and rising areas that 
 the thickest deposits of detritus, the most extensive foldings, and the 
 greatest ejections of volcanic matter have occurred. There has thus been 
 a permanence of the position of the continents and oceans throughout 
 geological time, but with many oscillations of these areas, producing 
 submergences and emergences of the land. In this way we can reconcile 
 the vast vicissitudes of the continental areas in difiFerent geological 
 periods with that continuity of development from north to south, and 
 from the interiors to the margins, which is so marked a feature. Wo 
 have for this reason to formulate another apparent geological paradox, 
 namely, that while in one sense the continental and oceanic areas are 
 permanent, in another they have been in continual movement. !N'or does 
 this view exclude extension of the continental borders or oi' chains of 
 islands beyond their present limits, at certain periods ; and indeed the 
 general principle already stated, that subsidence of the ocean bed has 
 produced elevation of the land, implies in earlier periods a shallower ocean 
 and many possibilities as to volcanic islands, and low continental margins 
 creeping out into the sea ; while it is also to be noted that there are, as 
 already stated, bordering shelves, constituting shallows in the ocean, 
 which at certain periods have emorged as land. 
 
 We are thus compelled to believe in the contemporaneous existence 
 in all geological periods, except perhaps the earliest of them, of three 
 distinct conditions of areas on the surface of the earth. (1) Oceanic 
 areas of deep sea, which always continued to occupy in whole or in part 
 the bed of the present ocean. (2) Continental plateaus and marginal 
 shelves, existing as low flats or higher table-lands liable to periodical 
 submergence and emergence. (3) Lines of plication and folding, more 
 especially along the borders of the oceans, forming elevated portions of 
 land, rarely altogether submerged and constantly affording the material 
 of sedimentary accumulations, while they were also the seats of powerful 
 volcanic ejections. 
 
 In the successive geological periods the continental plateaus when 
 submerged, owing to their vast extent of warm and shallow sea, have 
 been the great theatres of the development of marine life and of the de • 
 position of organic limestones, and when elevated they have furnished 
 the abodes of the noblest land faunas and floras. The mountain belts, 
 especially in the north, have been the refuge and stronghold of land life 
 in periods of submergence, and the deep ocean basins have been the 
 perennial abodes of pelagic and abyssal creatures, and the refuge of mul- 
 titudes of other marine animals and plants in times of continental eleva- 
 tion. These general facts are full of importance with reference to the 
 
I 
 
 ADDREP?. 19" 
 
 question of the succession of formations and of life in tho geological history 
 of the earth. 
 
 So much time has been occupied with these general views that it 
 would be impof sible to trace the history of the Atlantic in detail through 
 tho agoa of th(j Palojozoic, Mesozoic, and Tertiary. We may, however, 
 shortly glance at tho changes of the three kinds of surface already re- 
 ferred to. Tho bed of the ocean seems to have remained on the whole 
 abyssal, but there were probably periods when those shallow reaches of 
 the Atlantic which stretch across its most northern portion, and partly 
 separate it from the Arctic basin, presented connecting coasts or con- 
 tinuous chains of isUnds sufiicicnt to permit animals and plants to pass 
 over.' At certain periods also there were not unlikely groups of volcanic 
 islands, like the Azores, in the temperate or tropical Atlantic. More espe- 
 cially might this be the case in that early time when it was more like 
 the present Pacific ; and the line of the great volcanic belt of the Mediter- 
 I'anean, the mid Atlantic banks, the Azores, and the "West India Islands 
 point to the possibility of such partial connections. These were stepping- 
 stones, so to speak, over which land organisms might cross, and some of 
 these may be connected with the fabulous or prehistoric Atlantis.'^ 
 
 In the Cambrian and Ordovician periods the distinctions, already 
 referred to, into continental plateaus, mountain ridges, and ocean depths 
 were first developed, and we find already great masses of sediment accu- 
 mulating on the seaward sides of the old Laurentian ridges, and internal 
 deposits thinning away from these ridges over the submerged continental 
 areas, and presenting very dissimilar conditions of sedimentation. It 
 would seem also that, as Hicks has argued for Europe, and Logan and 
 Hall for America, this Cambrian age was one of slow subsidence of the 
 land previously elevated, accompanied with or caused by thick deposits of 
 detritus along the borders of the subsiding land, which was probably covered 
 with the decomposing rock arising from long ages of sub-aerial waste. 
 
 In the coal-formation age, its characteristic swampy flats stretched in 
 some places far into the shallower parts of the ocean.^ In the Jurassic 
 the American continent probably extended further to sea than at present. 
 In the Wealden age there waa much land to the west and north of Great 
 Britain, and Professor Bonney has directed attention to the evidence of 
 
 « 
 
 ' It would seem, from Geikie's description of the Faroe Islands, that they may be 
 a remnant of such connecting land, dating from the Cretaceous or Eocene period. 
 
 ' Dr. Wilson has recently argued that the Atlantis of tradition was really America, 
 and Mr. Hyde Clarke has associated this idea with the early dominance in Western 
 Europe of the Iberian race, which Dawkins connects with the Neolithic and Bronze 
 ages of archasology. My own attention has recently been directed, through specimens 
 presented to the McGill' College Museum, to the remarkable resemblances in cranial 
 characters, wampum, and other particulars of the Guanches of the Canaries with 
 aborigines of Eastern America — resemblances which cannot be accidental. 
 
 ■ I have shown the evidence of this in the remnants of Carboniferous districts 
 once more extensive on the Atlantic coast of Nova Scotia and Cape Breton (Acadian 
 Geology). 
 
«0 , KEronT~1886. 
 
 the existence of this land as far back as the Trias, while Mr. Slarkie 
 Gardiner lias insisted on connecting links to the southward as evidenced by 
 fossil plants. So late as the Post-Glacial, or early human period, large 
 tracts now submerged formed portions of the continents. On the other 
 hand the internal plains of America and Europe were often submerged. 
 Such submergences are indicated by the great limestones of the Paleo- 
 zoic, by the chalk and its representative beds in the Cretaceous, by the 
 Nummulitic formation in the Eocene, and lastly by the great Pleistocene 
 submergence, one of the raost remarkable of all, one in which nearly the 
 whole northern hemisphere participated, and which was probably sepa- 
 rated from the present time by only a few thousands of years.* These 
 submergences and elevations were not always alike on the two sides of 
 the Atlantic. The Salina period of the Silurian, for example, and the 
 Jurassic, show continental elevation in America not shared by Europe. 
 The great subsidences of the Cretaceous and the Eocene were proportion- 
 ally deeper and wider on the eastern continent, and this and the direction 
 of the land being from north to south cause more ancient forma^of life to 
 survive in America. These elevations and submergences of the plateaus 
 alternated with the periods of mountain-making plication, which was 
 going on at intervals at the close of the Eozoic, at the beginning of the 
 Cambrian, at the close of the Silnro- Cambrian, in the Permian, and in 
 Europe and Western America in the Tertiary. The series of changes, 
 however, affecting all these areas was of a highly complex character, and 
 embraces the whole physical history of the geological ages. 
 
 We may note here that the unconformities causedjby these movements 
 and by subsequent denudation constitute what Le Conte has called ' lost 
 intervals,' and one of the most iL.portant of which is supposed to have 
 occurred at the end of the Eozoic. It is to be observed, however, that as 
 every such movement is followed by a gradual subsidence, the seeming 
 loss is caused merely by the overlapping of the successive beds deposited. 
 
 We may also note a fact which I have long ago insisted on,' the regu- 
 lar pulsations of the continental areas, giving ns alternations in each 
 great system of formations of deep-sea and shallow-water beds, so that 
 the successive groups of formations may be divided into_^triplets of shal- 
 low-water, deep-water, and shallow-water strata, alternating in each 
 period. 
 
 But I must here call your attention to still another geological parodox, 
 namely, that the deep sea, which is so great a barrier to the passage of the 
 shallow-water animals, seems, under certain conditions, to afford facilities 
 for the transmission of land animals and plants. The connections esta- 
 
 ' The recent surveys of the Falls of Niagara coincide with a great many evidences 
 to which I have elsewhere referred in proving that the Pleistocene submergence of 
 America and Europe came to an end not more than ten thousand years ago, and was 
 itself not of very great duration. Thus in Pleistocene times the land must have been 
 submerged and re-elevated in a very rapid manner. 
 
 2 Arcadian Geology, 1865, 
 
ADDRESfi. 21 
 
 blished by the observations of the Challengery and so well expounded by 
 Wallace and Homsley,' between the florns of oceanic islands and the con- 
 tinents, establish this conclusively. Thus the Bermudas, altogether recent 
 islands, have been stocked by the agency chiefly of the ocean currents 
 and of birds, with nearly 150 species of continental plants, and the facts 
 collected by Hemsley as to the present facilities of transmission, along with 
 the evidence afforded by older oceanic islands which have been receiving 
 animal and vcgotablo colonist" for longer periods, go far to show that, 
 time being given, the sea actually affords facilities for the migrations of 
 the inhabitants of the land, greater than those of continuous continents. 
 
 In referring to the ocean basins we should bear in mind that there are 
 three of these in the northern hemisphere— the Arctic, the Pacific, and 
 tho Atlantic. De Ranco has ably summoned up the known facts as to 
 Arctic geology, and more irecently Dr. G. M. Dawson has prepared for 
 the Royal Society of Canada a resume and map of what is known of the 
 geology of the Arctic basin,^ in comparison with Canadian geology. From 
 this it appears that this area presents from without inwards a succession 
 of older and newer formations from the Eozoic to the Tertiary, and that 
 its extent must have been greater in former periods than at present, 
 while it must have enjoyed a comparatively warm climate. The relations 
 of its deposits and fossils are closer with those of the Atlantic than with 
 those of the Pacific, as might be anticipated from its wider opening into 
 the former. Blandford has recently remarked on the correspondence of 
 the marginal deposits around the Pacific and Indian oceans,^ and Dr. 
 Dawson informs me that this is equally marked in comparison with the 
 west coast of America,* but these marginal areas have not yet gained much 
 on the ocean. In the North Atlantic, on the other hand, there is a wide belt 
 of comparatively modern rocks on both sides, more especially toward the 
 south, and on the American side ; but whilo there appears to be a perfect 
 correspondence on both sides of the Atlantic, and around the Pacific 
 respectively, there seems to be less parallelism between the deposits and 
 forms of life of the two oceans as compared with each other, and less 
 correspondence in forms of life, especially in modern times. Still in the 
 
 ' Continental and Island Life ; Botany of the • Cliallenger * Expedition. 
 
 ' Meeting of May 1886. The paper is not yet published. 
 
 ' A singular example is the recurrence in New Zealand of Triassic rocks and fossils 
 of types corresponding to those of British Columbia. A curious modem analogy 
 appears in the works of art of the Maoris with those of the Haida Indians of the 
 Queen Charlotte Islands, and both are eminently Pacific in contradistinction to 
 Atlantic. 
 
 * Journal of Geological Society, May 188rf. Blandfoxd's statements respecting the 
 mechanical deposits of the close of the Palaeozoic in the Pacific area, whether these 
 are glacial or not, would seem to show a correspondence with the Permian conglome- 
 rates and earth-movements of the Atlantic area ; but since that time th'i Atlantic 
 has enjoyed comparative repose. The Pacific also seems to have reproduced the 
 conditions of the Carboniferous in the Cretaceous age, and seems to have been less 
 affected by the great changes of tihe Pleistocene. 
 
92 KEPOUT— 1886. 
 
 earlier geological ages, as might have boon anticipated from the imper- 
 fect development of the continents, the same forms of life charactoriHe 
 the whole ocean from Australia to Arctic Amoric! ind indicate a grand 
 unity of Pacific and Atlantic life not equalled in later times,' and which 
 speaks of contemporaneity rather than of what has been termed homo, 
 taxis. 
 
 We may pause here for a moment to notice some of the effects of 
 Atlantic growth on modern geography. It has given us rugged and 
 broken shores composed of old rocks in the north, and t wer formations 
 and softer features toward the south. It has given us «,re:inal moun- 
 tain ridges and internal plateaus on both sides of the sea. ft has pro- 
 duced certain curious and by no means accidental correspour^c, ^et* of the 
 eastern and western sides. Thus the solid basis on which tlie British 
 Islands stand may be compared with Newfoundland and Labrador, the 
 English Ghannel with the Gulf of St. Lawrence, the Bay of Biscay with 
 the Bay of Maine, Spain with the projection of the American land at 
 Cape Hatteras, the Mediterranean with the Gulf of Mexico. The special 
 conditions of deposition and plication necessary to these results, and their 
 bearing on the character and productions of the Atlantic basin would 
 require a volume for their detailed elucidation. 
 
 Thus far our discussion has been limited almost entirely to physical 
 causes and effects. If we now turn to the life history of the Atlantic, 
 wo are mf at the threshold with the question of climate, not as a thing 
 fixed and immutable, but as changing from age to age in harmony with 
 geographical inutations, and producing long cosmic summers and winters 
 of alternate warmth and refrigeration. 
 
 We can scarcely doubt that the close connection of the Atlantic and 
 Arctic oceans is one factor in those remarkable vicissitudes of climate ex- 
 perienced by the former, and in which the Pacific area has also shared in 
 connection with the Antarctic Sea. No geological facts are indeed at first 
 sight more strange and inexplicable than the changes of climate in the 
 Atlantic area, even in comparatively modem periods. We know that in 
 the early Tertiary perpetual summer reigned as far north as the middle 
 of Greenland, and that in the Pleistocene the arctic cold advanced, nntil 
 an almost perennial winter prevailed, half way to the equator. It is no 
 wonder that nearly every cause available in the heavens and the earth has 
 been invoked to account for these astounding facts. 
 
 It will, I hope, meet with the approval of your veteran glaciologist 
 Dr. Crosskey if. neglecting most of these theoretical views, I venture 
 to invite your attention in connection with this question chiefly to the old 
 Lyellian doctrine of the modification of climate by geographical changes. 
 Let us, at least, consider how much these are able to account for.^ 
 
 ' Daintree andEtheridge, 'Queensland Geology,' Journal Geological Society, August 
 1872 ; R. Etheridge, Junior, • Australian Fossils,' Trans. Phys. Soc, Edin. 1880. 
 ' The late Mr. Searlcs V. Wood, in an able summary of the possible causes of the 
 
ADI)UE8S. 23 
 
 The uccan is a groat ccjualiser of extremes of torapcraturo. It does 
 tills by its great capacity for heat and by its cooling and heating power 
 when paHsing from the solid into the li((uid and gaseous status, and the 
 reverse. It also acts by its mobility, its currents serving to convey heat 
 to great distances or to cool the air by the movement of cold icy waters. 
 The land on the other hand coola or warms rapidly, and can transmit its 
 influence to a distance only by the winds, and the influence so transmitted 
 is rather in the nature of a disturbing than of an ecinalising cause. It 
 follows that any change in the distribution of land and water must aflect 
 climate, more especially if it changes the character or course of the ocean 
 currents.* 
 
 At the present time the North Atlantic presents some very pecnliar 
 and in some respects exceptional features, whicli are most instructive with 
 reference to its past history. The great internal plateau of the American 
 continent is now dr ' land ; the passage across Central America between 
 the Atlantic and Pacific is blocked ; the Atlantic opens very widely to the 
 north ; the high mass of Greenland towers in its northern part. The 
 effects are that the great equatorial current running across from Africa and 
 embayed in the Gulf of Mexico, is thrown northward and eastward in the 
 Gulf Stream, acting as a hot water apparatus to heat up to an exceptional 
 degree the westorn coast of Europe. On the other hand, the cold Arctic 
 current from the polar seas is thrown to the westward, and runs down 
 from Greenland past the American shore.^ The pilot chart for June of 
 this year shows vast fields of drift ice on the western side of the Atlantic 
 as far south as the latitude of 40°. So far, therefore, the Glacial age in that 
 part of the Atlantic still extends ; this at a time when, on the eastern 
 side of the Atlantic, the culture of cereals reaches in Norway beyond the 
 Arctic Circle. Let us inquire into some of the details of these phenomena. 
 
 The warm water thrown into the North Atlantic not only increases 
 the temperature of its whole waters, but gives an exceptionally mild 
 climate to Western Europe. Still the countervailing influence of the 
 
 succession of cold and warm climates in the northern hemisphere, enumerates no 
 fewer than seven theories which have met with more or less acceptance. These are : — 
 
 1. The gradual cooling of ti.e earth from a condition of original incandescence. 
 
 2. Changes in the obliquity of the ecliptic. 
 
 3.' Changes in the position of the earth's axis of rotation. 
 
 4. The effect of the precession of the equinoxes along with changes of the eccen- 
 tricity of the earth's orbit. 
 
 5. Variations in the amount of heat given off by the sun. 
 
 6. Dififerences in the temperature of portions of space passed through by the 
 earth. 
 
 7. Differences in the distribution of land and water iu connection with the flow 
 of oceanic currents. 
 
 ' Von Woeickoff has very strongly put these principles in a Review of Croll's 
 recent book, Climate and Cosvwlogy ; American Journal of Sdence, March 1886, 
 
 ' I may refer bcre to the admirable expositions of these effects by the late 
 Dr. Carpenter, in hia papers on the results of the explorations of the Challenger. 
 
24 REPORT— 1886. 
 
 Arctic cnrrentE and tbe d.'eenland ice is sufficient to permit icebergs 
 "which creep down to the mouth of the Strait of Belle Isle, in the latitude 
 of the south of England, to remain unmelted till the snows of a succeed- 
 ing winter fall upon them. Now let us suppose that a subsidence of land 
 in tropical America were to allow the equatorial current to pass through 
 into the Pacific. The effect would at once be to reduce the temperature 
 of Norway and Britain tc that of Greenland and Labrador at present, 
 while the latter countries would themselves become colder. The northern 
 ice, drifting down into the Atlantic, would not, as now, be melted rapidly 
 by the warm water which it meets in the Gulf Stream. Much larger 
 quantities of it would remain undissolved in summer, and thus an accu- 
 mulation of permanent ice would take place, along the American coast 
 at first, but probably at length even on the European side. This would 
 still further chill the atmosphere, glaciers would be established on all the 
 mountains of temperate Europe and America,' the summer would be kept 
 cold by melting ice and snow, and at length all Eastern America and 
 Europe might become uninhabitable, except by arctic animals and plrnts, 
 as far south as perhaps 40° of north latitude. This would be simply a 
 return of the Glacial age. I have assumed only one geographical change ; 
 but other and more complete changes of bcj^sidence and elevation might 
 take place, with effects on climate still more decisive ; more especially 
 would this be the case if there were a considerable submergence of the 
 land in temperate latitiides. 
 
 We may suppose an opposite case. The high plateau of Greenland 
 migh', subside or be reduced in height, and the openings of Baffin'" 3ay 
 and the North Atlantic might be closed. At the same time the interior 
 plain of America might be depressed, so that, as we know to have been 
 the case in the Cretaceous period, the warm waters of the Mexican Gulf 
 would circulate as far north as the basins of the present great American 
 lakes. In these circumstances there would be an immense diminution of 
 the sources of floating ice, and a correspondingly vast increase in the sur- 
 face of warm water. The effects would be to enable a temperate flora to 
 subsist in Greenland, and to bring all the present temperate regions of 
 Europe and America into a condition of subtropical verdure. 
 
 It is only necessar/ to add that we know that vicissitudes not dis- 
 similar from those aboTe sketched have actually occurred in compara- 
 tively recent geological times, to enable us to perceive that we can dis- 
 pense with all other causes of change of climate, though admitting that 
 some of them may have occupied a secondary place.'* This will give us 
 in dealing with the distribution of life the great advantage of not being 
 
 • According to Bonney, the west coast of Wales is about 12° above the average for 
 its latitude, and if reduced to 12" below the average its mountains would have large 
 glaciers. 
 
 * More especially the ingenious and elaborate arguments of CroU deserve con- 
 sideration ; and, though I cannot agree with him in his Qtain thesis, I gladiy acknow- 
 ledge the great utility of the work he has done. 
 
ADDRESS. 25 
 
 tied tip to definite astronomical cycles of glaciation, which may not 
 always suit the geological facts, and of correlating elevation and subsid- 
 ence of the land with changes of climate affecting living beings. It will, 
 however, be necessary, as Wallace well insists, -that we shall hold to that 
 degree of fixity of the continents in their position, notwithstanding the 
 submergences and emergences they have experienced, to which I have 
 already adverted. Sir Charles Lyell, more than forty years ago, pub- 
 lished in his * Principles of Geology ' two imaginary maps which illus- 
 trate the extreme effects of various distribution of land and water. In 
 one all the continental masses are grouped around the equator. In the 
 other they are all placed around the poles, leaving an open equatorial 
 ocean. In the one case the whole of tho land and its inhabitants would 
 enjoy a perpetual summer, and scarcely any ice could exist in the sea. 
 In the other the whole of the land would be subjected to an arctic climate, 
 and it would give off immense quantities of ice to cool the ocean. But 
 Lyell did not suppose that any such distribution as that represented in 
 his maps had actually occurred, though this supposition has been some- 
 times attributed to him. He merely put what he regarded as an extreme 
 case to illudtrate what might occur under conditions less exaggerated. 
 Sir Charles, like other thoughtful geologists, was well aware of the 
 general fixity of the areas of the continents, though with great modifica- 
 tions in the matter of submergence and of land conditions. The union, 
 indeed, of these two great principles of fixity and diversity of the con- 
 tinents lies a the foundation of theoretical geology. 
 
 We can now more precisely indicate this than was possible when Lyell 
 produced his * Principles,' and can reproduce the conditions of our con- 
 tinents in even the more ancient periods of their history. Some examples 
 may be taken from the history of the American continent, which is more 
 simple in its arrangements than the double continent of Europ-asia. 
 We may select the early Devonian or Erian period, in which the magni- 
 ficent flora of that age — the earliest certainly known to us — made its 
 appearance. Imagine the whole interior plain of North America sub- 
 merged, so that the continent is reduced to two strips on the east and 
 west, connected by a belt of Laurentian land on the north. In the great 
 mediterranean sea thus produced the tepid water of the equatorial current 
 circulated, and it swarmed with corals, of which we know no less than 
 one hundred and fifty sp'-'iies, and with other forms of life appropriate 
 to warm seas. On tho islands and coasts of this sea was introduced 
 the Erian flora, appearing first in the north, and with that vitality and 
 colonising power of which, as Hooker has well shown, the Scandinavian 
 flora is the btst modern type, spreading itself to the south.' A very simi- 
 
 > As I have elsewhere endeavoured to show {Report on Silurian and Devonian 
 Plants of Canada), a warm climate in the Arctic region seems to have afforded the 
 necessary conditions for the great colonising floras of all geological periods. Gray 
 had previously illustrated the : tme fact in the case of the more modern floras. 
 
 > 
 I 
 
26 REroRT— 1886. 
 
 lar distribution of land and water in the Cretaceons age gave a warm and 
 equc jle climate in those portions of North America not submerged, and 
 coincided with the appearance of the multitude of broad-leaved trees of 
 modern types introduced in the early and middle Cretaceous, and which 
 prepared the way for the mammalian life of the Eocene. We may take 
 a still later instance from the second continental period of the later Pleisto- 
 cene or early Modern, when there would seem to have been a partial or 
 entire closure of the North Atlantic against the Arctic ice, and wide exten- 
 sions seaward of the European and American land, with possibly consider- 
 able tracts of land in the vicinity of the equator, while the Mediterranean 
 and the Gulf of Mexico were deep inland lakes.' The effect of such con- 
 ditions on the climates of the northern hemisphere must have been pro- 
 digious, and their investigation is rendered all the more interesting be- 
 cause it would seem that this continental period of the post-Glacial age 
 was that in which man made his first acquaintance with the coasts of the 
 Atlantic, and possibly made his way across its waters. 
 
 We have in America anci'mt periods of cold as well as of warmth. I 
 have elsewhere referred to the boulder conglomerates of the Huronian, 
 of the Cambrian and Ordovician, of the Mill ?-grit period of the Car- 
 boniferous and of the early Permian ; but v^ Ad not venture to aflSrm 
 that either of these periods was comparable in its cold with the later 
 glacial age, still less with that imaginary age of contmentar glaciation 
 assumed by certain of the more extreme theorists.* These ancient con- 
 glomerates were probably produced by floating ice, and this at period i 
 when in areas not very remote temperate floras and faunas could flourish. 
 The glacial periods of our old continent occurred in times when the 
 surface of the submerged land was opened up to the northern currents, 
 drifting over ic mud and sand and stones, and rendering nugatory, in 
 so far at least as the bottom of the sea was concerned, the effects of the 
 superficial warm streams. Some of these beds are also peculiar to the 
 eastern margin of the continent, and indicate ice-dfift along the Atlantic 
 coast in the same manner as at present, while conditions of greater 
 •warmth existed in the interior. Even in the more recent Glacial age, 
 while the mountains were covered with snow and the lowlands sub- 
 merged under a sea laden with ice, there were interior tracts in some- 
 what high latitudes of America in which hardy forest trees and her- 
 baceous plants flourished abundantly ; and these were by iiu means 
 exceptional * interglacial * periods. Thus we can show that while from 
 the remote Huronian period to the Tertiary the Amencan land occupied 
 the same position as at present, and while its changes were merely 
 changes of telative level as compared with the sea, these have so in- 
 fluenced the ocean currents as to cause great vicissitudes of climate. 
 
 Without entering on any detailed discussion of that last and greatest 
 
 • Da^kins, Popular Science Monthly, 187S. 
 
 * Notes on Post-Pliocene of Canada. Pre- Cambrian Oaloiers, Qeol. Mag., 1880. 
 
ADDRESS. 27 
 
 Glacial period which is beat known to us, and is more immediately con- 
 nected with the early history of man and the modern animals, it may bo 
 proper to make a few general statements bearing on the relative import- 
 ance of sea-borne and land ice in producing those remarkable phenomena 
 attributable to ice action in this period. In considering this question it 
 must be borne in mind that the greater masses of floating ice are pro- 
 duced at the seaward extremities of land glaciers, and that the heavy 
 field-ice of the Arctic regions is not so much a result of the direct freez- 
 ing of the surface of the sea as of the accumulation of snow precipitated 
 on the frozen surface. In reasoning on the extent of ice action, and 
 especially of glaciers in the Pleistocene age, it is necessary to keep this 
 fully in view. Now in the formation of glaciers at present — and it 
 would seem also in any conceivable former state of the earth — it is neces- 
 sary that extensive evaporation should conspire with great condensation 
 of water in the ^olid form. Such conditions exist in mountainous 
 regions sufficiently near to the sea, as in Greenland, Norway, the Alps, and 
 the Himalayas ; but they do not exist in low arctic lands like Siberia or 
 Grinnel-land nor in inland mountains. It follows that land glaciation 
 has narrow limits, and that we cannot assume the possibility of great 
 confluent or continental glaciers covering the interior of wide tracts of 
 land. No imaginable increase of cold could render this possible, inas- 
 much as there could not be a sufficient influx of vapour to produce the 
 necessary condensation ; and the greater the cold, the Jess would be the 
 evaporation. On the other hand, any increase of heat would be felt 
 more rapidly in the thawing and evaporation of land ice and snow than 
 on the surface of the sea. 
 
 Applying these very simple geographical truths to the North Atlantic 
 continents; it i^ easy to perceii^e that no amount of refrigeration could 
 produce a continental glacier, . because there could not be sufficient eva- 
 poration and precipitation to aflbrd the necessary snow in the interior. 
 The case of Greenland is often referred to, but this is the case of a high 
 mass of cold land with sea, mostly open, on both sides of it, giving, there- 
 fore, the conditions most favourable to precipitation of snow. If Green- 
 land were less elevated, or if there were dry plains around it, the case 
 would be quite djfierent, as Nares has well shown by his observations on 
 the summer veBdure of Grinnel-land, which, in the immediate vicinity of 
 North Greenland, presents very difierent conditions as to glaciation and 
 climate.* If the plains wei^e submerged, and the Arctic currents allowed 
 free access to the interior of the continent of America, it is conceivable 
 that the mountainous regions remaining out of water would be covered with 
 snow and ice, and there is the best evidence that this actually occurred 
 in the Glacial period ; but with the plains out of water this would be im- 
 possible. We see evidence of this at the present day in the fact that in 
 
 ' These views have been admirably illustrated by Von WceickofE in the paper 
 already referred it and in previous geographical papers. 
 
28 REPORT— 1886. 
 
 uuasaally cold winters the great precipitation of snow takes place south of 
 Canada, leaving the north comparative ly bare, while aa the temperature 
 becomes milder the area of snow deposit moves farther to the north. 
 Thus a greater extension of the Atlantic, and especially of its cold ice- 
 laden arctic currents, becomes the raost potent cause of a glacial age. 
 
 I have long maintained these conclusions on general geographical 
 grounds, as well as on the evidence afforded by the Pleistocene deposits of 
 Canada ; and in an address the theme of which is the ocean I may be excused 
 for continuing to regard the supposed terminal moraines of gi'eat continental 
 glaciers as nothing but the southern limit of the ice-drift of a period of 
 submergence. In such a period the southern margin of an ice-laden sea 
 where its floe-ice and bergs grounded, or where its ice was rapidly melted 
 by warmer water, and where consequently its burden of boulders and 
 other debris was deposited, would necessarily present the aspect of a 
 moraine, which by the long continuance of such conditions might assume 
 gigantic dimensions. Let it be observed, however, that I fully admit the 
 evidence of the great extension of local glaciers in the Pleistocene age, and 
 especially in the times of partial submergence of the land. 
 
 I am quite aware that it has been held by many able American 
 geologists * that in North America a continental glacier extended in tem- 
 perate latitudes from sea to sea, or at least from the Atlantic to the 
 Bocky Mountains, and that this glacier must, in many places, have 
 exceeded a mile in thickness. The reasons above stated appear, however, 
 sufficient to compel us to seek for some other explanation of the observed 
 facts, however difficult this may at first sight appear. With a depression 
 such as we know to have existed, admitting the Arctic currents along the 
 St. Lawrence Valley, through gaps in the Laurentian watershed, and 
 down the great plains between the Laurentian areas and the Rocky 
 Mountains, we can easily understand the covering of the hills of Eastern 
 Canada and New England with ice and snow, and a similar covering of 
 the mountains of the west coast. The sea also in this case might be 
 ice-laden and boulder-bearing as far south as 40", while there might still be 
 low islands far to the north on which vegetation and animals continued 
 to exist. We should thus have the conditions necessary to explain all the 
 anomalies of the glacial deposits. Even the glaciation of high mountains 
 south of the St. Lawrence Valley would then become explicable by the 
 grounding of floe-ice on the tops of these mountains when reefs in the sea. 
 In like manner we can understand how on the isolated trappean hill of 
 Beloeil, in the St. Lawrence Valley, Laurentian boulders far removed from 
 their native seats to the north are perched at a height of about 1,200 feet 
 on a narrow peak whero no glacier could possibly have left them. The 
 so-called moraine, traceable from the great Missouri Cotean in the west, to 
 the coasts of New Jersey, would thus become the mark of the western and 
 
 ' Kcport of Mr. Carvill Lewis in Penmylvania Geological Swrvey, 1884; also 
 Dana's Manual. 
 
ADDRESS. 29 
 
 southern limit of the sabsidence, or of the line along which the cold 
 currents bearing ice were abruptly cut off by warm surface waters. I 
 am glad to find that these considerations are beginning to have weight 
 "with European geologists in their explanation of the glacial drift of the 
 great plains of Northern Europe. 
 
 Whatever difficulties may attend such a supposition, they are small 
 compared with those attendant on the belief of a continental glacier, 
 moving without the aid of gravity, and depending for its material on the 
 precipitation taking place on the interior plains of a great continent. 
 
 I have elsewhere endeavoured to show, on the evidence found in Canada, 
 that the occurrence of marine shells, land plants, and insects in the glacial 
 deposits of that country indicates not so much the effect of general 
 interglacial periods as the local existence of conditions like those of 
 Grinnel-land and Greenland, in proximity to each other at one and the 
 same period, and depending on the relative levels of land and the distribu- 
 tion of ocean currents and ice drift. ^ 
 
 I am old enough to remember the sensation caused by the delightful 
 revelations of Edward Forbes respecting the zones of animal life in the 
 sea, and the vast insight which they gave into the significance of the 
 work on minute organisms previously done by Ehrenberg, Lonsdale, and 
 Williamson, and into the meaning of fossil remains. A little later the 
 soundings for the Atlantic cable revealed the chalky forcminiferal ooze of 
 the abyssal ocean ; still more recently the wealth of facts disclosed by the 
 Challenger voyage, which naturalists have not yet had time to digest, 
 have opened up to ua new worlds of deep-sea life. 
 
 The bed of the deep Atlantic is covered for the most part by a mud 
 or ooze largely made up of the debris of foraminifera and other minute 
 organisms mixed with fine clay. In the North Atlantic the Norwegian 
 naturalists call this the Biloculina mud. Further south the Ohallenger 
 naturalists speak of it as Globigerina ooze. In point of fact it contains 
 different species of foraminiferal shells, Globigerina and Orbulina being 
 in some localities dominant, and in others other species, and these changes 
 axe more apparent in the shallower portions of the ocean. 
 
 It is also to be observed that there are means for disseminating coarse 
 material over the ocean bed. There are in the line of the Arctic current 
 on the American coast great sand-banks, and off the coast of Norway 
 sand constitutes a considerable part of the bottom material. Soundings 
 and dredgings ofE Great Britain, and also off the American coast, have 
 shown that fragments of stone referable to Arctic lands are abundantly 
 strewn over the bottom along certain lines, and the Antarctic continent, 
 otherwise almost unknown, makes its presence felt to the dredge by the 
 abundant masses of crystalline rock drifted far from it to the north. 
 These are not altogether new discoveries. I had inferred many years ago, 
 
 ■ Notes on Pott-Pliocene of Canada, 1872. One well-marked interval only has been 
 established in the glacial deposits o£ Canada. 
 
30 REPORT— 1886. 
 
 from stones taken up by the hooks of fishermen on the banks of New- 
 foundland, that rocky material from the north is dropped on these banks 
 by the heavy ice which drifts over them every spring, that these stones 
 are glaciated, and that after they fall to the bottom sand is drifted over them 
 with sufficient velocity to polish the stones and to erode the shelly cover- 
 ings of Arctic animals attached to them.' If then the Atlantic basin 
 were upheaved into land we should see beds of sand, gravel, and boulders 
 with clay flats and layers of marl and limestone. According to the 
 Challenger Reports, in the Antarctic seas S. of 64° there is 1 lue mud with 
 fragments of rock in depths of 1,200 to 2,000 fathoms. The stones, some 
 of them glaciated, were granite, diorite, amphibolite, mica schist, gneiss, 
 and quartzite. This deposit ceases and gives place to Globigerina ooze 
 and red clay at 46° to 47° S., but even further north there is sometimes as 
 much as 49 per cent, of cr3^stalline sand. In the Labrador current a 
 block of syenite weighing 490 lbs. was taken up from 1,340 fathoms, and 
 in the Arctic current 100 miles from land was a stony deposit, some stones 
 being glaciated. Among these were smoky quartz, quartzite, limestone, 
 dolomite, mica schist, and serpentine ; also particles of monoclinic and 
 triclinic felspar, hornblende, augite, magnetite, mica, and glaucorite, the 
 latter no doubt formed in the sea-bottom, the others drifted from i^i^ozoic 
 and Paleeozoic formations to the north.' 
 
 A remarkable fact in this connection is that the great depths of the 
 6ea are as impassable to the majority of marine animals as the land itself. 
 According to Murray, while twelve of the OlialUnger's dredgings taken 
 in depths greater than 2,000 fathoms gave 92 species, mostly new to 
 science, a similar number of dredgings in shallower water near the land 
 gave no less than 1,000 species. Hence arises another apparent paradox 
 relating to the distribution of organic beings. While at first sight it 
 might seem that the chances of wide distribution are exceptionally great 
 for marine species, this is not so. Except in the case of those which 
 enjoy a period of free locomotion when young, or are floating and pelagic, 
 the deep ocean sets bounds to their migrations. On the other hand the 
 spores of cryptogamic plants may be carried for vast distances by the 
 wind, and the growth of volcanic islands may effect connections which, 
 though only temporary, may afford opportunity for land animals and 
 plants to pass over. 
 
 With reference to the transmission of living beings across the Atlantic, 
 we have before us the remarkable fact that from the Cambrian age on- 
 wards there were on the two sides of the ocean many species of inverte- 
 brate animals which were either identical or so closely allied as to be 
 possibly varietal forms .^ In like manner the early plants of the Upper 
 Silurian, Devonian, and Carboniferous present many identical species ; but 
 
 ' Notes on Post-PUooene of Canada, 1872. 
 ' Oeneral Report, ' Challenger ' Expedition. 
 
 * See Davidson's Monographt on Braohiopodt; 'EXhetidige, Address to Oeologiaal 
 Society of London, Woodward, Address to Qeologisti Association, also Barrande's Special 
 
ADDRESS. 81 
 
 this identity becomes less marked in the vegetation of the more modern 
 times. 
 
 In so far as plants are concerned, it is to be observed that the early 
 forests were largely composed of cryptogamous plants, and the spores of 
 these in modern times have proved capable of transmission for great 
 distances. In considering this we cannot fail to conclude that the union of 
 simple cryptogamous fructification with arboreal stems of high complexity, 
 so well illustrated by Dr. Williamson, had a direct relation to the neces- 
 sity for a rapid and wide distribution of these ancient trees. It seems 
 also certain that some spores, as, for example, those of the Rhizocarps,* 
 a type of vegetation abundant in the Paleeozoic, and certain kinds of 
 seeds, as those named ^theotesta and Pachytheca, were fitted for flotation. 
 Farther, the periods of Arctic warmth permitted the passage around the 
 northern belt of many temperate species of plants, just as now happens 
 with the Arctic flora ; and when these were dispersed by colder periods 
 they marched southward along both sides of the sea on the mountain chains. 
 
 The same remark applies to northern forms of marine invertebrates, 
 which are much more widely distributed in longitude than those further 
 south. The late Mr. Gwyn Jeffreys, in one of his latest communications 
 to this Association, stated that 54 per cent, of the shallow-water 
 mollusks of New England and Canada are also European, and of the 
 deep-sea forms 30 out of 35 ; these last of course enjoying greater 
 facilities for migration than those which have to travel slowly along the 
 shallows of the coasts in order to cross the ocean and settle themselves 
 on both sides. Many of these animals, like the common mussel and 
 sand clam, are old settlers which came over in the Pleistocene period, 
 or even earlier. Others, like the common periwinkle, seem to have been 
 slowly extending themselves in modem times, perhaps even by the agency 
 of man. The older immigrants may possibly have taken advantage of lines 
 of coast now submerged, or of .warm periods, when they could creep 
 around by the Arctic shores. Mr. Herbert Carpenter and other natu- 
 ralists employed on the Challenger collections have made similar state- 
 ments respecting other marine invertebrates, as, for instance, the Echino- 
 derms, of which the deep-sea crinoids present many common species, and 
 my own collections prove that many of the shallow-water forms are 
 common. Dall and Whiteaves^ have shown that some mollusks and 
 Eohinoderms are common even to the Atlantic and Pacific coasts of 
 North America ; a remarkable fact, testifying at once to the fixity of these 
 species and to the manner in which they have been able to take advantage 
 of geographical changes. Some of the species of whelks common to the 
 Gulf of St. Lawrence and the Pacific are animals which have no special 
 
 Memoirg on the Brachiopods, CJephalopdds, ^'c. ; and Hall, Palceontology of Nero York ; 
 Billings, Reports on Canadian Fosdls ; and Matthews, Cambrian of Nero Bruntmok, 
 Trans. R. S. C. 
 
 ' See paper by the author on Palaeozoic Rhizocarps, Chicago Trans. 1886. 
 ^ * Dall, Report on Alaska; Whiteaves, Trans. R. S. C. 
 
32 REPORT— 1886. 
 
 locomotive powers even when young, but they are northern forms not 
 proceeding far south, so that they may have passed through the Arctic 
 seas. In this connection it is well to remark that many species of 
 animals have powers of locomotion when young, which they lose when 
 adult, and that others may have special means of transit. 1 once found 
 at Gaspo a specimen of the Pacific species of Coronula, or whale-barnacle, 
 the 0. reginm of Darwin, attached to a whale taken in the Gulf of St. 
 Lawrence, and which had probably succeeded in making that passage 
 around the north of America, which so many navigators have essayed in 
 vain. 
 
 It is to be remarked here that while many plants and marine inverte- 
 brates are common to the two sides of the Atlantic, it is different with 
 land animals, and especially vertebrates. I do not know that any fossil 
 insects or land snails or millipedes of Europe and America are specifically 
 identical, and of the numerous species of batrachians of the Carboniferous 
 and reptiles of the Mesozoic all seem to be distinct on the two sides. 
 The same appears to be the case with the Tertiary mammals, until in the 
 later stages of that great period we find such genera as the horse, the 
 camel, and the elephant appearinj^ on the two sides of the Atlantic ; but 
 even then the species seem difierrnt, except, in the case of a few northern 
 forms. 
 
 Some of the longer-lived mollnsks of the Atlantic furnish suggestions 
 which remarkably illustrate the biological aspect of these questions. 
 Our familiar friend the oyster is one of these. The first known oysters 
 appear in the Carboniferous in Belgium and in the United States of 
 America. In the Carboniferous and Permian they are few and small, 
 and they do not culminate till the Cref ceous, in which there are no less 
 than ninety-one so-called species in America alone ; but some of the largest 
 known species are found in the Eocene. The oyster, though an inhabitant 
 of shallow water, and very limitedly locomotive when young, has sur- 
 vived all the changes since the Carboniferous age, and has spread itself 
 over the whole northern hemisphere.' 
 
 I have collected fossil oysters in the Cretaceous clays of the coulees of 
 Western Canada, in the Lias shales of England, in the Eocene and Cre- 
 taceous beds of the Alps, of Egypt, of the Red Sea coast, of Judea, and 
 the heights of Lebanon. Everywhere and in all formations they present 
 terms which are so variable and yet so similar that one might suppose all 
 the so-called species to be mere varieties. Did the oyster originate 
 separately en the two sides of the Atlantic, or did it cross over so 
 promptly that its appearance seems to be identical on the two sides ? 
 Are all the oysters of a common ancestry, or did the causes, whatever 
 they were, which introduced the oyster in the Carboniferous act over 
 again in later periods r Who can tell ? This is one of the cases where 
 causation and development — the two scientific factors which jonstitute the 
 
 ' White, Report U.S. Qeol. Survey, 1882-83. 
 
ADDRESS. 33 
 
 basis of what is vaguely called evolution — cannot easily be isolated. I 
 would recommend to those biologists who discuss those questions to addict 
 themselves to the oyster. This familiar mollusk has successfully pur* 
 sued its course and has overcome all its enemies, from the flat-toothed 
 selachians of the Carboniferous to the oyster dredgers of the present 
 day, has varied almost indefinitely, and yet has continued to bo an oyster, 
 unless indeed it may at certain portions of its career have temporarily 
 assumed the disguise of a Gryphroa or an Exogyra. The history of such 
 an animal deserves to be traced with care, and much curious information 
 respecting it will be found in the report which I have cited. 
 
 But in these respects the oyster is merely an example of many forms. 
 Similar considerations apply to all those Pliocene and Pleistocene mollusks 
 which are found in the raised sea-bottoms of Norway and Scotland, on 
 the top of Moel Tryfaen in Wales, and at similar great heights on the 
 hills of America, many of which can be traced back to early Tertiary 
 times, and can be found to have extended themselves over all the seas 
 of the northern hemisphere. They apply in like manner to the ferns, 
 the conifers, and the angiosperms, many of which we can now follow 
 without even specific change to the Eocene and Cretaceous. They all 
 show that the forms of living things are more stable than the lands 
 and seas in which they live. K we were to adopt some of ne modem 
 ideas of evolution we might cut the Gordian knot by supposing that, as 
 like causes can produce like effects, these types of life have originated 
 more than once in geological time, and need not be genetically connected 
 with each other. But while evolutionists repudiate such an application of 
 their doctrine, however natural and rational, it would seem that nature 
 still more strongly repudiates it, and will not allow us to assume more 
 than one origin for one species. Thus the great question of geographical 
 distribution remains in all its force, and, by still another of our geologi- 
 cal paradoxes, mountains become ephemeral things in comparison with 
 the delicate herbage which covers them, and seas are in their present 
 extent but of yesterday when compared with the minute and feeble 
 organisms that creep on their sands oir swim in their waters. 
 
 The question remains. Has the Atlantic achieved its destiny and 
 finished its course, or ui'e there other changes in store for it in the 
 future ? The earth's crust is now thicker and stronger than ever before, 
 and its great ribs of crushed and folded rock are more firm and rigid 
 than in any previous period. The stupendous volcanic phenomena mani- 
 fested in Mesozoic and early Tertiary times along the borders of the 
 Atlantic have apparently died out. These facts are in so far guarantees of 
 permanence. On the other hand, it is known that movemente of elevation 
 along with local depression are in progress in the Arctic regions, and a 
 great weight of new sediment is being deposited along the borders of the 
 Atlantic, especially on its western side, and this is not improbably con- 
 nected with the earthquake shocks and slight movements of depression 
 which have occurred in North America. It is possible that these slow 
 
34 REPORT— 1886. 
 
 and .secular movomonts may go on unintorruptodly until conHidorablo 
 changes are produced ; but it is quite as likely tiiat they may bo retarded 
 or reversed. 
 
 It is possible, on the other hand, that after the long period of quiescence 
 which has elapsed there may bo a now settlement of the ocean-bed, ac- 
 companied with foldings of the ornst, especially on the western side of the 
 Atlantic, and possibly with renewed volcanic activity on its eastern mar- 
 gin. In either case a long time relatively to our limited hnman chrono- 
 logy may intervene before the occurrence of any marked change. On the 
 whole the experience of the past would lead us to expect movements and 
 eruptive discharges in the Pacific rather than in the Atlantic area. It is 
 therefore not unlikely that the Atlantic may remain undisturbed, un- 
 less secondarily and indirectly, until after the Pacific area shall have attained 
 to a greater degree of quiescence than at present. But this subject is one 
 too much involved in uncertainty to warrant us in following it farther. 
 
 In the meantime the Atlantic is to us a practically permanent ocean, 
 varying only in its tides, its currents, and its winds, which science has 
 already reduced to definite laws, so that we can use if we cannot regulate 
 them. It is ours to take advantage of this precious time of quietude, and 
 to extend the blessings of science and of our Christian civilisation from 
 shore to shore until there shall be no more sea, not in the sei;se of that 
 final drying-up of old ocean to which some physicists look forward, but 
 in the higher sense of its ceasing to be the emblem of unrest and disturb- 
 ance, and the cause of isolation. 
 
 I must now close this address with a short statement of the general 
 objects which I have had in view in directing your attention to the geo- 
 logical development of the Atlantic. We cannot, I think, consider the 
 topics to which I have referred without perceiving that the history of 
 ocean and continent is an example of progressive design, quite as much 
 as that of living beings. Nor can we fail to see that, while in some im- 
 portant directions we have penetrated the great secret of Nature, in refer- 
 ence to the general plan and structure of the earth and its waters, and 
 the changes through which they have passed, we have still very much to 
 learn, and perhaps quite as much to unlearn, and that the future* holds 
 out to us and to our successors higher, grander, and clearer conceptions 
 than those to which we have yet attained. The vastness and the might 
 of ocean and the manner in which it cherishes the feeblest and most fragile 
 beings, alike speak to us of Him who holds it in the hollow of His hand, 
 and gave to it of old its boundaries and its laws ; but its teaching ascends 
 to a higher tone when we consider its origin and history, and the manner 
 in which it has been made to build up continents and mountain-chains, 
 and at the same time to nourish and sustain the teeming life of sea and 
 land.