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The following diagrams illustrate the method: L'exemplaire film6 fut reproduit grdce d la gdn6rosit6 de I'dtablissement pr§teur suivant : La bibliothdque des Archives publiques du Canada Les cartes ou les planches trop grandes pour dtre reproduites en un seul clich6 sont film6es d partir de Tangle sup6rieure gauche, de gauche d droite et de haut en bas, en prenant le nombre d'images n^cessaire. Le diagramme suivant illustre la mdthode : 1 2 3 1 2 3 4 5 6 f^y.^'^^A ^ff^-^-^^' \ ^ l» , ., V vtyyx^^^ < ' GEOLOGICAL HISTORY 3 OK THE NORTH ATLANTIC. PRESIDENTIAL ADDRESS. BY SIIJ .1. WILLIAM DAWSON, < ..M.(i.. .M.A..LLI).. F.H.S., F.d.S., Principal aiul Vice-Chancellor of Mcaill I niversity, Montreal, Cuniidu. MONTR KAL; PRINTED BY THE GAZETTE 1»UINTING COMPANY. 1886. i. 7^ im^^ ^ , > , > > ; vmi^-r^ m >^»^ i # t ■ ■'- > % r ,1 ,M, *• .. » r 1 '..X,,' • -(;V /' '■^A .t . ■•». I r "X. v'.i '■A ''■"• I V I ) ' I.. >' '>■ < • a • ■.: ) , \ •■ S .A', , : - ■> * , '.' .J V'!- % •<•■■ V « gfiti^U ^,$.s'ocijitla» for the gtrtvanccmcut of ^cicure. BiKMixGUAM Meeting, ScrTEMBEit, 188G. THE GEOLOGICAL HLSTORY OF THE NORTH ATLANTIC. PRESIDENTIAL ADDRESS. BY SIR J. WILLIAM DAWSON, <.'.jr.(J., J[.A.,LL.D., F.Ii.S., F.G.S., Principal and Vice-Chancellor of MoGill I'liiversity, Muiitical, Canada. MONTREAL: riilNTED BY THE GAZETTE PKINTING COMPANY. 188G. %^^' '\1^ I I' Oi((j ) PRESIDENTIAL ADDRESS BEFORE TniC British Association for the Advancement of Science, SEPTEINIIiKR, 18BG. SIR J. WILLIA:\I DAWSON, CJI.ii.. M.A., LliD., F.H.S., F.(J.S., Priiicipnl iiml Vico-Chanoollor of McCill University, Aloutrcal, Caiuulu. TwKNTY-oNK yoixvH Iiavo passod away .since the last meet- inii,-()ftlie IJi'itisIi Association in this o-i-cat central city of Eno-laiul. At the third Binuiii-;liani meetini;- — that of 18(J5— I had the pleasure ol' bcini;- i)rcsoiit, and had the honour of bein«,^one of the Vice-Presidents of the Geolo-idcal Section. At that nieetinn-, my friend John Phillips, one of the founders of the Association, occupied the Presidential chair, and 1 cannot better introduce what 1 have to say this evening than by quotin^• the chxiuent woi-ds with which he then oi)ened his address : — 'Assembled foi- the third time in this busy centre of industrious England, amid the roar Of engines and clang of hammers, where the sti'ongest pow- prs of natui-e are trained to work in the fairy chains oi art. how softly and fittiiii^ly fulls upon I lie oai' the Jiccont of sciunco, tho frk'iid of that iirt, iiiul thu^'uido of that industry ! Here where Priestley analysed tho air, and Walt obtained the maNtei'y over siciiin, it well lieconios ilu; students of na- ture to gather rcniml the standard which ihoycari'ied so far into the fields of knowledge. And when on other occasions wo moot in quiot colleges ami academic halls, how gladly welcome is tho union of fresh discoveries and new inventions with the solid and venerable truths which ai'c there ti'oa- sui'cd and taught. Long may such union hxM ; the fair alliance of cultivated thought and practical skill ; for by it, laboui' is tlignilieJ and science fertilised, and tho contlition of human society exalted.' Those wore the wonls of a man who, while earnest in tho pursuit of science, was full of broad and kindly sympathy tbi- his fcllow-meu and of hope- ful contidenco in the future. Wo have but to tui-n to the twenty Reports of this Association, issued since 18 J.'), to see tho reali-ation of that union of science and art to which ho so contidently looked foiward, and to appreciate the stu- pendous results which it has achieved. Jn one departmerit alone — that to which my predecessor in this (diair so elo- quently aelf lived to see a great revolution in this I'es- pect at Oxford. But no one in 18G5 coulil have anticipated that immense develo])ment of local schools of science of which your own Mason rollege and your admirable tech- nical, industrial, and art schools are eminent examples. Based on the general education given by the new system of Boanl schools, with which the name of the late W. Iv P'or- ster will over bo honourably connected, and extending its influence upward to special training, and to the highest uni- versity examinations, this new scientific cultui-e is opening- paths of honoural)le ambition to the men and women of En- gland scai'cely dreamed of in 18(55. I sympathise with the earnest anneal of Sir Lyon Playfaii", in his Abei'deon ad- dross in nfvour of scientific education ; but visiting Kngland at i«aro intervals, J am naturally more impressed with the progress that has been made than with the vexatious delays wliich liiivo occurred, and T am perhaps hotter ahle to appreciate the vast stridt-s that have heon taken in the diroi'lioM of tliat conipleto and all-porvudini,' culture in science whidi he has so ahl^- advocated. No one could liave anticipated twenty years a^-o that a Birniini,'ham manufacturer, in whose youthful days tlioro wore no s(diools of Kcionco for the people, was ahout to endow a collei^e, not only worthy of this groat city, but one of its brightest ornaments.' Nov could any-one have fore- seen the i;-rcat di'vol()|)ment of local scientific societies, like your Midland Institute and Philosophical Society, which are now flourishing in ovi'vy large town and in many of those of less magnitude. The period of twenty-one years that has elapsed Biiu-e the last Birmingham meeting has also been an era of ])ublic museums and laboratories for the teaching of science, from the magniliccnt national institu- tions at South Kensington and those of the great univer- sities and their colleges down lo those of the schools and tield clul)s ill 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 more and more their range of reading, and of eli'ort to keep abreast of the advance in their several dei)artments. Lastly, these twenty- one years have been charactci ised as the ' coming of age ' of that great system of philo-opliy wiih which the names of (hi-ee Knglislimen, Darwin. Spencer, and Wallace, are associated as its founders. Whatever opinions one may en- tertain as to the sulliciency and tinality of that philosophy, there can be no question as to its intluence on sciontitic thought. On the one hand, it is inaccurate to compare it with things so entirely ditfei-ent as the discover}' of the cliemical elements and of the law of gravitation. On the other, it is .scarcely fair to chai-acteriso it as a mere 'confused development' of the mind of the age. It is indeed a new attempt of science in its maturer 3-ears to ' It \v;is in ]Siir-, tliat Sir Josiali Mason was, quietly and witliout any public uoU\ bej.'inninj; to lay the foundation of liis orphana-ie at Erdlne great and awful (juestions ol" the ultimate destin\' ol humanit\', and of ils relations to its Ci'oator, which must always he nearer to the human heart than any of the acdiievements of science on its own ground. In entering on siudi (pieslions, we shouM proceeil with cau- tion and reverence, feeling lliat we arc on holy ground ; and that though, like Moses of old. we may ho ai'tned with all the leai-ningof our time, we are in the presence of that whi(di, while il hums, is not consumed; a mystery whi(di neither ohservation, experiment, nor induction can evo;- fully solve. In a recent address, the la'e Pre>ident of the Royal Society called atlcMtion to the tact that within the lilelime of the oldei' men of science of the present day, the greater ])arl of the vast hoc lyofl viiowletlu'e inciu( led in nioilerii sciences of physics, chemistry, hiology, and geology, has heen accu- mulatetl,and the most imj)ort:mt advances made in its ajijili- cation to such common and familiar things as the railway, ocean navigation, the eU'Ctric telegraph, elei-tric lighting, the tele])hone. the geim theory of disea>e, the use of anaes- thetics, the pi'oce.ssesof metallurgy, and thedj'cing of fahrics. Even since the last meeting in this city, much of this great work has heen done, and has led to general results of the most marvellous kind. What at that time could have ap- peared more chimerical than the opening up, hy the enter- 2)i'iso of one Hiilish colony, of a shorter road to the east by wa}' of the extreme west, realizing what was happily called hy Milton andC'headIc 'the new North-west Passage,' mak- iiii-' .lapiiii llio next lUM^fliboiir of Caiiadii on (he west, and ollorin<^ to Hri(aiii a now way to lior Kastorn possossions; or than Iho possiliiliiy of tliis Association lioldinui; a siu'cossful nu'i'tini;- on thoollici- side of the Atlantic ? To havo ventiiroU to |)i'e(lic( siu'h lliin<;'s in lH(i5, would liavt appcaroil ([iiitG vlNionaiy, yot yon aro now invited to moot in Australia, and may ])rocced (liithor hy tl»o dinadian I'acitic Railway and its new lines of stoamei'.s, i-oturnini? by the Suez Canal.' To-day tlii.s is quite as feasible as the Canadian visit would have boon in IStj"). It is science which has thus broui;'ht the once widely separated parts of the world nearer to eacli other, ami which is breaking down those ^•eoifraphical bai-riers which have separated the ilitlerent portions of our witlely extended JJritish race. Its work in this is not yet complete. Its goal to-day is its stailing-pcnnt to-morrow. It is as far as at any previous time from seeing the limit of its con(|uests ; and every victory gaineil is but the opening of the way lor a farthei' advance. Jiy its visit to Canada, the British Association has asserted its imperial character, and has consolidated the scientitic interests of llei" Majesty's dominions, in advance of that great gathei'ing of the industrial pi'oducts of all parts of the empire now on (exhibition in London, and in advance of any political plans of imperial federation. There has even been a project before us foi' an international scientitic convention, in which the great lOnglish republic of America shall take part, a pi-qject, 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 1881. As a Canadian, as a past President of the American Asso- ciation, and now honoured with the Presidency of this Association, I may be held to re])resent in my own person the scientitic union of the Jh'iti.>li islands, of the various Colonies and of the great liepublic, which, whatevci- the difficulties attending its formal accomplishment at present, ^ It is expected that, on the completion of the connections of the Canadliiu rucilic Railway, the time from ocean to oceuii may be reduced to llG hours, and from Loudon to iloug Kong to twenty- seven days. 8 is certain to load (o an actual and real co-operation in scien- titic work. In furtherance of tins, i aiu i^hul (o see hero today influential i-cpi-esentativcs of most of the Hriti.'-h Colonies, of India, and of the United States. We welcome here, also, delegates from other countries; and though the barrier of language may at piesent prevent a lar<^er union, we may entertain the hope that ]>ritain, America, India, and the Colonics, working togethei- in the interestof science, may ultimately render oui- Eng'li.->h tongue the most general vehicle of scientific thought and discovery, a consummation of which 1 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 buttles and assured itsalvance. In looking back to ISO'), there rise before me the once familiiir countenances of Phillips, Miirchison, L^-ell, Forbes, .letfVeys, Jukes, RoUeston, Miller, Spotti.^woode, Fairbiiirn, Gassiot, Carpen- tei-, and a host of othei-s, present in full vigor at that meet- ing, but no more with us. Those were veterans of science ; but, alas! many then young and lising in fame are also numbe.ed with the dead. It may be that before another Birmingham meeting, many of us, the older membei's now, will have parsed away. Put those men have lelt l)ehind them inetfaceable monuments of their work, in which the}' still survive, and we rejoice to believe that, though dead to us, they live in the company of the groat and good of all ages who have enteietl into the unseen universe where all that is high and holy and beautiful, must go on accumuhiting till the time of the restitution of all things. Let us follow their example anil carry on their work, as God may give us power and opportunity, gathering jii-ecious stores of know- ledge and of thought, in the belief that all truth is inimoi-tal, and must go on for ever bestowing blessings on maekind. Thus ^vill the memory of the might}- 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 lime longer with general or personal matters, but rather to take the oppor- 9 tunity afforded by this address to invite your attention to some topics of scientitic interest. Jn attempting to do this, I must liave belbie me the warninij^ conveyed hy Professor Huxley, in the address to whieli I have ah-eady refei-rcd, that in our time, science, like Tai'peia, nniy he crushed with the weight of the i-ewards bestowed on her. In other woixls, it is impossible for any man to keep pace with the pi'ogress of more tlian one limited branch of science; and it is equally impossible to find an audience of scientitic men of whom anything moi'e than ameio fraction can be expected to take an inteiest in an}' one subject. There is, however, some con- solation in the knowledge that a speaker who is sulHciently sim|)le for those who are advanced specialists in other depart- ments, will of necessity' be also sutticicntly simple to be understood by the genei-al public who are specialists in nothing. On this princi])le, a geologist of the old school, accustomed to a gi'cat vai iety of woi k. may hojjc so to scat- ter his tiro as to reach the greater ]>art of the audience. In endeavouring to secure this end, J have sought inspiration from that ocean which connects rathei- tiian separates Britain and America, and may almost be said to be an English sea— the North Atlantic. The geological history of this dci)iession of the cai th's ciiist, and its relation to the continental masses which limit it, ma}- furnish a theme at once generally intelligible and connected with great ques- tions as to the structure and history of the eai'th, which have excited the attention alik'e of the physicists, geoloL,Msts, bio- logists, geographei's and ethnulogists. Should I, in treating of these questi(^ns, ap[)ear to be somewhat alirujit and dog- matic, and to indicate rather than state the ev'idence of the general views announced, I tiustyou will kino notice that a mass or belt of land surrounds each pole, and that the northern rinu; sends otf to the southward three vast tongues of land and of mountain chains, tei'ininalinii; respectively in South America, South Atrica, and Australia, towards which feebler and insular processes ai'e given otf by the Antarctic coniinental mass. This, as some geog-raidiers have observed,' give-* a rudely three-ribbed aspect to the earth though two of the rib- are crowded together and form the lOuroji-asiau mass oi- double continent, while the third is isolated in the single coniiiunl of America. He might also observe that llu' northern girdle is cut across, so that the Atlantic o|)ens by a wide space into the Arctic Sea, while the Pacitic is contracted towai'd the north, but continent with the Antai'ctic Oc-ean. The Atlantic i•^ also i-elativelj' dee])er and less cumbered with islands than the Pacific, whi(di has the higher ridges near its shores, constituting what some visitors to the Pacitic coast of Amei-ica have not inaptly called the ' back of the world,' while the wider slopes face the nari'ower ocean, into which, for this leason. the greater |)arl of the di'ainage oi the LukI is poured.- The Pacitic and Atlantic, though both depi'essions or llattenings of tlu^ earth, are, as we shall tind, ditleient in age, (diaracter, and conditions; and the Atlantic, though the smaller, is tiie older, and. frwm the geological ])oint of view, in some i-es- pects, the more important of tht' two. If our imaginary observer had the means of knowing anything of the rock formations of tin- c<)nlinenls, he would notice that tho>e bounding IheNorth At lantic are. ingeneral. of great age — some l)clonging to the Laurentian system, ' Dana, Mdinidt of Gmlixjij, introductory part. Green, VcMlrjix of a Molten GJolu , lias summed up these lact.s. - "Sir. Mellard lu'ade, in two J'residcntial addresses before the Geological Society of Liverpool, has illustrated this point and its geological consequences. I 11 On the otlier hand, he would see that many of the mountain i'an,<>-os aloni;- tlie Pacific are comparatively new, and that modei'n i earth. It is po])ularly supposed that we know nothing ot' this beyond a sui)ei'ficial crust perhaps averag- ing 511,000 to 100,000 feel in thickness. It is true we have no means of exi»loration in the earth's inteiior, but the con- Joined labours of physicists and geologists have now pro- ceeded sulHciently fiir to throw much inferential light on the subject, and to enable us to make some general attlrma- 12 tions with cci-talnty ; and these it is the moi'e necessary to state (listinclly, since tliey are often treated as mere subjects of speculation and fruitless di>cussi()!). (1) Since the dawn of /.geological science, it has been evident that tlie crust on which wo live must be supported on a plastic oi- partially li(|uid mass of heated rock, approxi- mately uniform in (quality under the whole of its ai'ea. This is a legitimate conclusion from the wide disti-ibution of vol- canic phenomeiui, and fi'om th'i 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, l)ut this is now genei-ally abandoned, and this interior heated and plastic layer is regarded as morelv an under-erust. (2) Wo have reason to believe, as the I'esult of astrono- mical investigations, ' that, notwithstanding the plasticity or liquidity of the under-ci-nst, the mass of tlie eartli — its nucleus as we may call it — is ])ractically solid and of great density and hardness. Thus we have the a])parent paradox of a solid yet fluid earth ; solid in its astrononiieal relations, licjuid or ])lastic for the purposes of voleanic action and su- ])ei'tieial niovenier.ts. - (;j) The plastic sub-erust is not in a state of diy igneous fusion, but in that, condition of ariueo-igneous oi- hydro- thermic fusion which arises iVoin the action of heat on »noist substances, and which may either be regarded as a fusion or as a species ot solution at a veiy high temperature. This we learn from the ))henoniena of volcanic acticni. and tVom ' TIi)j)kins, ;>r;illet, Sir William Thrmsnn, and Prof. G. II. Darwin maintain the sulidity and rigidity (it the earth on astronomical j:ronnds ; hut ditl'eront conclnsions liavo heen reaihcd hy Ilennesoy, Delannay, and Airy. In Anierieu, Barnard and Crosby, Dutton, Le Conte, and Wadsworth iiav(>. discnssed these (luestions. - An ohje(!lion lias been taken to the ellect tliat the suppasod ellipsoidal form of tlu^ equator is inconsistent witli a pla-tic sub- err !t this ellipsoidal form is not absolutely certain, or, if it eXi s very minute. lionney has, in a recent leitture, sn) The contraction of the eai-th's intei'ior b}- cooling and by the emission of material from below the ovei'-crust, has caused this ciMist to ]>ress downward, and therefore laterally, and so to elfcct great bonds, folds, and plications ; and these, moditieil subsequently by surface denudation, constitute mountain chains and continental plateaus. As JIall long ago pointed out," such lines of folding have been produced moi'o especially where thick sediments had been laid down on the sea bottom. Thus we have here another appai'ont paradox, ntimely, that the elevations of the earth's crust occur in the places whore the greatest burden of de- tritus has been laid down upon if, and wliero consequently tho crust has been sofiened and depre-^sed. AVe must be- wai'e, in this connection, of exaggerated notions of the extent of contraction and of crumpling reciuii'cd to foi-m mountains. Jjonneyhas well shown, in lectures delivered at the London Institution, that an amount ot conti-action, al- most ina))preciable in comparison with the ult of all the long series of observations calculations, and discussions since the time of Werner and Hut ton, and in which a vast number of able ])bysicistH and luituralists have borne a part, because they may be con- sidered as certain deductions from our actual knowledge and becau.se they lie at the foundation of a rational ])hysical geology. We may popularise these deductions by comparing the earth to a drupe or stone-fruit, such as a j)lum or peach somewhat dried up. It has a large and intensely hard stone and kernel, a thin j)ulp made up of two layers, an inner more dense and dark-coloured, and an outci- less dense ami lighter-coloured. These constitute the un.lei'-crust. On the outside it has a thin membi'ane or over-crust. In the i)ro- cess of di-ying it has slightly shrunk, so as to produce ridges ami hollows of the outer crust, and this outer crust has ' See recent papers of Oldluun and Fisher, in G,nIof/ira/ Maqa-ine and J'liHosophical Mmjazim:, .Tnly 188U, Also Perociio, Reiv/. Pn- fahrs. I'aris, 18SG. I 16 cracked in some places, allo\vinhed, as if b}' lateral ])ressure emanating from the sea itself. We cannot, for example, look at a geolog-ical map of America' without jierceiving that the Appalachian ridges, which intervene lietween the Atlantic and the St. Lawi eiice valley, have heen driven bodily back by a force acting from the east, and that they have resisted this pres- sure only where, as in the Gulf of St. Lawrence and the Catskill region of New Yoi-k, 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 Adii'ondack Mountains. The admirable work Ix'giin by my friend and fellow-student Professor James Nicol, followed u]) by Hicks, Lapwoith, and others, and now, after long controversy, fully contirined by the recent observations of the geological sur- vey of Scotland, has shown the most intense action of the same kind on the cast side of the ocean in the Scottish high- lands ; and the more widely distributed Eozoic rocks of Scandinavia may be apj^ealed to in further evidence of this. ' ' Address to the Geniofjical Section, by Trof. Judd, Aberdeen Meelinjr, 1SS5. According to Rogers, tlie cruinpling of tlio Appala- chians has reduced a breadtli of 158 miles to about 00. 11 If we now inquire as to tiio cause of the Atlantic t ^o back to the time when tlio areas occupied by the Atlantic and its boundini^ coasts wei'O parts of the shoreless sea in which the earliest ifiicisses or sti'atitied granites ot'thc LMurentiaii age were being laid down in vastly extended beds. These ancient cr^'stalline rocks have been the subject of much discu>si()n and controversy, and as they con>titut(! the lowest and probably the firmest pai-t of the Atlantic sea-bed. it is necessary to inquii'e as to their origin and history. Dv. IJonney, the laie President of the Geolo- gical Society, in his Anniversary addi-ess, and Dr. Sterry Hunt, in an elaborate p:iper communicated to the Roj'al Society of C.'anada, have ably summed u|) the hypotheses as to the origin ot the oldest J^aurentian beds. At the basis of these hypoth(!ses lies the admission that the immensely thick beds of orthotdase gneiss, wdiich are the oldest sti-atiried rocks known to iis. aie substantially the same in composition with the upjjcr oi- silieious magma or layoi' of the under- crust. Tluy are, in short, its matei'ials either in their primi- tive condition or merely re-arranged. One theoiy considei's them as oi-iginal i)i'oducts of cooling, owing their lamination merely to the successive stnges of the process. Another view refers them to the waste and re-ari-angement of the materials of a previously massive gi'anite. Still another holds that all our gi'anites really arise from the fusion of old gneisses of oi'igihally aqueous oi'igin, while a foui'th refers llie gneisses themselves to molecular changes etl'ectcd in gi-anite 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 ) Endoplutoyiic, or that Avhi!' Werner." (5) C'rcniticov ilydro-thermie, which supposes the action of heated waters, penetrating- helow the crust, to he constantly hrimiiuii; up to the surface mineral matters in solution and depositing those so aw to form fels- pathic and other ;-ocl m to the moderate degi'oo in which it was oi-iginally hold byLyoll, is still valid. Nothing can bo more certain than that the comjjosition of the J>auren- tian gneisses forbids us to suppose that they can be ordi- nary sediments metamorphosed. They are rocks ])eculiar in their origin, and not paralleled, unless exceptionally, in ' Lyell, Kopp, Reusoh, Judd. &.c. '^ Scrope, De LaBeche, Daubr^'O. ^ liuut, Transactions Royal Society of Canada, 1885. 19 he flicoiy L'tlll citlicf is wjis I ho iiic. which holow t ho c mhioral Corm fels- Ihal they sediment, nnstancos, 11(1 of sub- trincipally • hai (lolled ou^'Iit we :v (hat tho Voiii with- ocall}' dis- tvv held in 1 liy heated nii lidding r)ee!m ? It ■ncies may )sits. This iiaintain in I American )e in every ry which, 1 then dis- ^e in which othiiii!; can he Lauren- an be o idl- es peculiar tionally, in later times. On tho other hand, they have undoubtedly experienced very importani chariui'C' to'ind soniuch attention now ^iven in this comitry to the old erystallino rocks, and to tlieii- study mieroscopieaUy and chemically as well as in the Held, a woi'U in wlTudi Sorly and All[)ort woi'c pioneei'H. As a pupil of the late Professor Jameson ot' JOdinburi^h, my own attention was oaily attractuil to tho study of minerals and rocks as tho stahlo foundations of geological scionce; and so far back as IHU I had leai'ut oj' the Into Mr. Sanderson, of lvlinburi;h, who woi-ketl at Nicol's sections,' bow to slice rocks and fossil>; and since that time 1 have been in the habit of examining- everything- with the microscope. The modern developments in this direction are therefore very gratifying to me, oven though, as is natural, they sometimes appear to Ik' pushed too fai- or their value overestimated. That the older gneisses wen- de])0silcd, not only in what is now the betl of the Atlantic, but also on thegretil continental areas of Amei-ica and Europe, anyone who considers tbo wide extent of these rocks reiiresented on the map recently published by Professor Hull can readily understand.' It is true that Hull suj)posos that the hasin of the Atlantic itself may have boon land at this time, but theie is no necessity for holding this view, more especially as the material of the gneiss could not have been dotiitu-. derived from sub-aerial decay of rock. Let us suppose, then, the tioor of old ocean covered with a flat pavement 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, llei-e we have some things certain, others most debateable. That tho cooling mass, especially if it was sending out volumes of softened rocky material, either in the exojjlutonic or in the cienitic Tmns. Royal Irish Acadermj* - And I believe at Wltliara's also. r:iml)i'iiin iiilly IVoin Ihc-^o last, I'iU'l'M'S. ijist rathor ,d Hoimich .'lystallino inieally as l[)()rt woi'o iiiuison of toil 10 tho da Lions of :1 lea nit of 1 at Nicol's i tlial tirno if with tho ■oction aru is natiiial, hoii- valiio ill what is ontiiicniiil aiders tho ip recently ind.-' It is untie itself ) necessity M'ial of the siib-ai'uial ^•ered with ich is now is orig'inal have some ho cooling" •f softened he crenitic thara's also. * 21 way, and pilini;' this on tho surface, must soon become too small foi' its ^hell, is apparent ; hut when and where would tho collapse, erushini;, and wrink'lini^ inevitable from this cau-e begin? When they began is indicated by the linos of mountain-chains which traverse tho Liiurontian districts; but the reason why is less apparent. Tlie moi'O oi" loss iine(iual cooling, hardening and conduct ivo ])ower of tho outer ci'iist we may readily assume. The di-iftage un- eiiually of water boi-nc detritus to the south-west by the bottom currents of the sea is another cause, and, as wo shall soon sec, most otfective. Still another is the greater cooling and hardening of the crust in the polar regions, and the tendency to colla|>so of tho equatorial protuberance from the slackening of tho earth's rotation, l^osides these, the inlei'iial tides of tho earth's suI)stanco at the times of solstici' would exert an obliijue )»ulling force on tho crust, which might tend to craclc it along diagonal lines. From whichever of these causes or the combination of tho whole, we know that, within tho Laiu'ontian time, folded portions of the earth's crust began to rise above the geni'i-al Mirface, in broad belts running from N.E. toS.^Y.,and from X.W. to S. 1']., where the older mountains of Ivistern America and Western iMirope now stand, and that the sul)>idence of the oceanic areas, allowed by this crumpling of the crust, per- mitted other areas on both sides of the Atlantic to form lin^'ted taldedands.' This was the commencement of a pro- cess repeated again and again in subsequent times, and which began in the middle Laurentian, wdien for the first time wo find lieds of quartzite, limestone, and iron oi'e,and graphitic beds, indicating that there was already bind ami water, and that tho sea. and |)crhapstlie land, swarmed with forms of ani- mal and plant life, unknown, for the most part, now. inde- pendently of the questions as to the animal nature of Eozoon, I hold that we know, as certainly as we can know anything ' Daubree's curious experiments on the contraction of caoutclioiic balloons, partially hardened by coatin<,' Avith varnish, show how small ine(iualitie3 of the crust, from whatever cause arising, mirrlit effect the formation of wrinkles, and also that transverse as well as longitudinal wrinklin<' uiiudit occur. 22 inferentially, the existence of those primitive forms of life. If [ were to conjeetui'o what were the early forms of plant and animal life, 1 would suppose that, just as in the Pahi'o- zoic, tho acroi;eiis culminated in i!:iu'antic and complex forest trees, so in the Laurentian, the ali^ic, the lichens, and the mosses grew to diniensions and assumed complexity of struc- ture unexampled in later times, and that, in the sea, the humbler forms of Protozoa and Ilydiozoa were the dominant types, but in giiijantic and complex forms. The land of this pei'iod was ])robal)ly limited, for the most ]iart, to hiuh lati- tudes, and its aspect, thoui,'h more riiii;i:,ed and abrupt, and of greater elevation, must have boon of that (diai-acter which we still see in the Liuroiitian hills. The distributiDU of this ancient land is indicated by the long lines of old Lauientian rock extending from the Labrador coast and the north shore of the St. Lawrence, and along the eastern slopes of the A])palachians in America, and the like i-ocks of the He- brides, the We-;torn Highlands, and the Scandinavian mountains. A small but intoi-esting I'omnant is that in the Malvern Hills, so well described by IIoll. It will bo well to note here and to fix on our minds, that these ancient i-idges of Eastern Ameidca and Western l^u'ope have Ijeon greatly denuded and wasted since Lnui'cntian times, and that it is along their eastern sides that the greatest sedimentary accumulations have been deposited. Fi'om this time dates the introduction of that dominance of existing causes which tbrms the basis of uidlbi'initarian- ism in geology, and which had to go on with various antl great modifications of detail, through the successive stages of the geological histoiy, till the land and water of the northei'n hemisphere attained to their ])rescnt complex structure. So soon as wo have a circumpolar belt oi' patches of Eozoic ' land and ridges running southward from it, wo enter on new and more complicated methods of growth of the continents and seas, Poi'tions of the oldest crys- talline rocks, i-aised out of the protecting water, were now eroded by aimos])heric agents, and especially by the car- ' Or Archaean, or pre-Cambrian, if these terms are preferred. I 23 "orms of life, ■ins of plant n the Piilii'o- )iii|)lex forest ens, and the xily of sti'uc- the sea, Hie the dominant land of this to hii^h lati- 1 ahrupt, and actor which hiition of this d Laurent ian north shore dopes of the ; of tiio lie- Scandinavian is that in the ill ho well to ncient i'id<>;os ! been i^i'oatly antl that it is sedimentary at dominance dformitaidaii- 1 various and jossivo stau'es water of the W(dlen stream would carry into the sea the products of the waste of land, soi-tirrg them into tine clays and coar- ser sands ; and the cold currents which clines of ejected igneous rocks, in the bed of the central Atlantic, theie aie no >uch accumulations. It must have been a flat, or slightly ridged, phite of the ancient gneiss, hard and resisting, though perhaps with a few cracks, through which igneous matter welled up, as in Icc^Iand and the Azores in more modern times. Jn this condition of things we have causes tending to pci-petuate and extend the distinctions of ocean and continent, mountain and plain, ali'cady begun ; and of these we nuiy more especially note the continued subsidence of the areas of greatest marine dcp<^sition. This has long attracted attention, and atfoids very convincing evidence of the connection of sodiinenfary ue])osit as a cau.se with the subsidence of the crust. ' We ai'e indebted to a French jdiysicist. M. Faye, - for an impoi-tant suggestion on this subject. It is that the se- diment accumulated along the>h()rcs()f the ocean presented an obstacle to radiation, and consetiuently to cooling of the crust, while the ocean floor, unprotected and unweighted, and constantly bathed witli currents of cold water having great power of convectMjii of heal, would be mori' ra])idly cooled, and so WDuld ijccome thickei- and stronger. This suggestion is complementary to the theoiy of I'rofessor Hall, that the areas of greatest deposit on the margins of ' f)utton in Jlc/iorf of VS. Giolngirtil Surnii, 1881. From facts stated in this report and in my Anididii Grolntiij, it is apparent that in the Western States anil in the cdallields ot Nova Scotia, slialiow- wiiter deposits have lieen laid down, up to thicknesses of 1U,(I(IU to 20,0(J() feet ill <'onne.ction with eoniinuous sulisidence. .See also a paper liy KicUetts in the (hul. Mutj. lS8o. It may be wi'll to add liere that this doctrine of the siibsidenee of wide areas hciiiL;' caused by (iei)OHition, does not justify the conclusion of certain >.dacialists that snow and ice liav(^ exerci.sed a like power in jihuial periods. lu truth, as will appear in the seijuel, ixreat aceuiiiiilatioiia of >now and ice require to be preceded by subsidence, and witle continental areas can never be covered with deep suow, wiiile, of course, ice can cause no addition of \vei.d rtain .ulacialists t:lacial i)eiio(ls. ilatinns of .-now vide continental if course, ice cun 25 . the ocean are necessarily those of greatest folding and con- sequent 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 tblds 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 ci'acked in many places, allowing the interior fluid matter to exude in volcanic ejections. It may be .said that all this supposes a permanent con- tinuance ofthe ocean-basins, whereas many geologists postu- late a mid-Atlantic continent ' to give the thick masses of detritus found in the older formations both in Kastcrn America and Western Kurope, and which thin otf in pro- ceeding into the ir.lerior of both continents. 1 prefer, with Hall, to consider these belts of .sediment as, in the main, the deposits of northern currents, and derived from Arctic land, and that like the gi-eat banks ofthe American coast at the present day, which are being buiU up by the present Arctic current, they had little to do with any direct drainage fiom the adjacent shore. We need not deny, however, that such ridges of land as existed along the Atlantic mai'gins were cont.ibuiing llu-ir quota of river-borne material. Just as on a still greater scale the Amazon an.l Mis.-, especially it is necessary to take into the account the existence of an Atlantic rid<:e of Caurentian rock on the west side of l':nroj)e,(.f which the Hebrides and the oldest rocks of Wales, Ireland, Western trance, uud Portugal are renmauts. 26 the ordinary i-casunii)^ r(!Hpoc,tini^ (lio necessity of conti- iientiil JU'Ciis ill llie piosoiil, ocean liasiiis \v<)iii(l actually ol)li^'o us to suppose that llie wliole of tlic oceans and con- tinents had i'epeat(vlly clian^'ed places. This consideration o])j)oses enormous physical dilUcultics to any theory of nllernalions of the oceanie and continental areas, except locally at their niari;ins. 1 would, howcA'cr, i-cfer you foi- a moi'O full discussion of these points to the address to he de- livered to-nioi'ri)\v by tlie President of (he (Jeological Section. But the pernianenco of the Atlantic depression does not exclude tlu' idea oi" successive subiner,!.(ences of the conti- nental plateaus and mari^inal slopes, alternating with per- iods of elevation, when tlu^ ocean retreated from the con- tinents and cont racted its limits. In this res])ect, the At- lantic of to(l:iy is much sinaller than it was in (hose limes wlien it spread widely over the continental plains and sloj)(ss, and mu(di lai'^er t h;in it has been in times of con- tinental elevation. This leads us to the further considei'a- tion (lia(, while (he ocean-heds have liccn sinkinn-, other areas have been beller su])portcd. and constitute the con- tinental plateaus ; and that it has been at or n(>ar tln^ .junc- tions of tlu'se sinkiui;- and risinii,- areas that thelhicke>t de- ])Osits of detritus, (he mo>t extensixt; foldinij;s, and the ^rea(es( ejections of volcanic matter have occuri'cd. There lias thus been a jtermanence of the position of (he condnents and oceans throui;;houl L;e()l()n;ical time, but with man}' oscillations of 'diese ai-eas, ]>roducinu; submeri;H'nces and emer,ii;ences of the land. In this way, we can i-ccimcih' the vast vicissitudes of the continental ai'cas in ditl'erent i;(M)lo- ^ical periods with that continuity of d(n'elo|)ment from nortli to south, and from (he in(eriors (o (he marL!;ins, which is so mai'ked a tea(ure. We have, for (his reason, to foi-mu- lalo anotbei' apparent i;'eol ordeal paradox, namely, that while, in one sense, tin- con(inen(al and oceaiuc areas are permanent, in another, they have been in continual move- ment. Nor does (his view exelude extension oftheconti- nen(al bordei's or of (diains of inlands beyonil (heir ju'esent linnts. a( certain periods; and indeed (he gcncj-al principle 27 if y of conti- uld iicliKilly Hiis and ('i)ti- •onsidoration y tlK'()ry (»!' reus, I'xccpl Cor you lor a •08.S to be do- js (leolo_i;i('al ion docs not of tho conti- w^ with 1 )('!■- IVoni tiie con- nect, lluj At- n (lioso times I plains and times of con- wv considcra- inkini!,-, otiior tulc iIk! con- iciir the June- It' tliicUcst de- ni;s, and the ii-red. 'riiei'o the continents t with many ei'i;'enees and I i-eeoneiUi the itt'ercnt i;-eol()- opment from iar,<;ins, wiiieh ison, to formu- namely, that mie areas are iiilinual movi'- ti of till' eonti- tlieir present lei'al principle already stated, tliat snhsidonee of tlie occan-hed has pro- duced elevation of the land, implies in eai'lier periotis a shallower ocean and many possihilities as to volcanic islands, and low continental mart!;iiis creej)irf,) Lines of pli- cation and foldim!;, more esjiecially aloii<;" the l)or t he histoi'v of the Atlantic in detail throui^h the aii;es of the Paheozoic, .Mesozoic, and Tertiary. We may, however, shortly glance at the chatii^M's of the three kinds of surface alreailv referred to. 'l"he bed 28 of tlio ocean scorns to Imve remained, on tlie wiiole, abyssal, but tlu've were pi-obably poi-iods wbeii tliosc sliallow i-eacbos of the Atlantic wliicli st retell across its most noi-tliern poi-- tion, ami partly sopai-ato it from the Arctic basin, prescntetl connectii)!^ coasts or coiifiiiuDiis cliains of islands snfTicieiit to permit animals and i)lants to ]iass ovei-.' At certain periods also tliore wore, not unlikely, groups of volcanic islands, like the A/oros, in the temperate or tropical Atlantic. Moi'O especially might this be the case in that early time when it was more like the ]n'oseiit Pacific ; and the lino of the i^rcat volcanic belt of the ^^editcrl•ancan. ihe mid Atlantic banks, the Azores and the West Fnilia Islands point to the possibility oi'such partial connections. These were steppiniir- stones, so tosjieak. ovi-r which land or<;-ani>>ms mit>'ht ci'oss, and some of these may l.)0 connected with the fabulous or prediistoric Atlantis.-' In the Canibiian ami Ordovician periods, the distinctions, already rcferi'tnl to, into continental ])lafeaus, mountain ridi^es, and ocean depths, Wi're tiist developed, and we tind. already, great masses of sediment accumulating on the sea- ward sides of the old Laurent ian ridges, and internal (U>posits thinning away from these ridges over the submerged con- tinental areas, and )n'e>enting dissimilai* conditions ol' sedi- mentation. It would seem also that, as Ilicdcs has argued for I'lurope, and Logan and Hall for America, this t'amlu'ian ago was one of slowsuiisidenceof the land pi-cviously elevated, accompanie 1 with or caused by thick deposits of detritus ' It wrmld seem, from (tcikie's description of tlu^ Faroe Islands that they may be a remnant (.»f such connecting land, dating from th(^ Cretaceous or Eocene period. -' Dr. WllsDU has recently argued tliat the Atlantis of tradition was really America, and Mr. llj'de ClarUe has associated this idea with the early dominance in western iMirope of toe Iberian race, which Dawkins connects witli the Neolithic and Bronze ages of arclueology. ^ly own attention has recently been directed, througli specimens presented to the IMcCiill Tollege Museum, by Mr. K. S. llalihurton, to tlie nnnarkable resemblance in cranial characters, w'ampum, and other particulars of the Guanches of the Canaries with aborgines of Eastern America — resemblances which cannot be accidi'ntal. 29 liolc, abyssal, allow reaches noi'thern por- sic, the American contineni probably ex- tended further to the sea than at ])re>ent. In the Wealden age, there was much land to the west and north of (Jreat Jjidtain, and Professor Bouncy has directed attention to the (•' ulenco of the existence (»f this land as far back as the Trias, wliileMr. Slarkie iiardiner has insisted on connecting links to the southwai'd as evidenced by fossil iilants. So late as the Post-glacial, or early human period, largo tracts, now submerged, formed portions of the continents. On the other hand, the interior ])lains of America and Kurope wc;e often submergetl. .Such submergences are indicated by the great limesbmcs of the Pahcozoic, by the chalk and its repre>enta- tive beds in the Cretaceous, by the Nummulitic formation in the Eocene, and lastly by the great Pleistocene submer- gence, one of the most lemarkableof all, one in which nearly the whole northern hemisphere i)articipatcd, and which was probably separated Irom the ])resent lime by only a fuw thousaiuU oi' years.- These submergence- and elevations wei e not always alike on the two sides of the Atlantic. The Salina period of the Silurian, for example, and the .lurassic, show continental elevation iu America not sluued by Europe. The ii'reatsuhsidcnccs of the Cretaceous and the Kocene were pro])ortionally deeper and wider on the eastei-n continent, ' I liave shown the evidenrc of tliis in the remnants of Carboni- fenius districts once more exteii.s'V(>- on the Atlantie coast of Nova Scotia and Cape Breton (Acadian Giologij.) - The recent surveys of the Falls of Niagara coincide witli a great many evidences to which I have elsewhere reiV-rred in proving that the Pleistocene submergence of America and Europe caiue to an end not more than ten thousand years ago, and was itself not of very great duration. Thus in Bleistocene times th.e land luiist have been submerged and re-elevated in a very rapid manner, 80 and this and the direction of the land boincj from north to south, cau^o more aiicicDt forms of litb to siirvivo in America. Those elevations and hulnneru'enci'sof the ])hiteansaltei'nalod with the i)eriods of moiintain-malcini^ plication, whicli was j^oin<5 on at intei'vals at tlio oloso of tlie l']o/oic, attlio l)eiiin- nini; of the Cambrian, at the close of the Sihiro-Cainl>rian, and in I^jurope and Western America in the Tertiaiy. Tlio soi'ios of chanj^es, however, affectini^ all these areas was of a liiii;]ily coin]>lex cliai-actor, and embraces the wliole pliysi- cal history of the ii'eolo!i;ical ai^es. We may here note tliat tlie unconformities caused by these movements and l)y subseiiuent denudation constitute what Lo Conto has called ' lost intervals,' ausidences of ^hich allowed inland spaces boar in mind lemisphore — e Ranee has geology in a h it ap|)earH a succession of older and newer formations from the Eozoic to the Ter- tiary, anil that its extent must have been greater in former periods than at pi-esoiit, while it must have oiijo^-ed a com- parati\oly warm oliiiiate from the Cambi'ian to the Pleisto- cene jioriod. 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. lilandford has recently remarked on the correspondence ol" the marginal deposits around the Pacific and Iiulian oceans,' and Dr. Dawson infoi-ms mo that this is equally marked in comparison with the west coa-^t of America,' but these marginal areas have not 3-et gained much on the ocean. In the North At- lantic, on the other hand, there is a wide belt of compara- tively modern rocks on both sides, more especially toward the south and uii the Amoriran side; but while there ajipeai's to be a perfect correspondence on both sides of the Atlantic', and around the Pacific I'ospoctively, there seems to bo less parallelism between the dojiosits and foimis of life of the two oceans as (■omj>ai'o(l with oacdi other, and less correspomlence in forms of life, especially in modoi-n times. Still in the earlier geological ages, as might have been anti- ci])atod from the imperfect devolo[)nient of the continents, the same forms of life characterise the whole ocean from Australia to Arctic America, and inilicate a grand unity of ' A singular example is the reeurronce in New Zoaland of Trias- sie rocks and fossils of types (corresponding to those (jf British Co- lumbia. A curious modern analogy appears in tiio works of art of the Maoris with tiioseof the llaida Indians of the Queen Charlotte islands, and botli are eiiiiuently Pacilie in ccjiitradistinction to Atlantic. '' Journal of Geological Sochti/, May 1880. Blaiidford's statements respecting the iiUHduuiical deposits of tlio close of the Palaxtzoic in the Indian ocean, wiiethor tiieso are glacial or not, would seem to show a correspondence with the I'ermian conglomerates and earth- movements (jf the Atlantic area ; but since that time, the Atlantic has enjoyed comi)arative rojxise. Tiie Pacific seems to have reproduced the conditions of the Carboniferous in tho Cretaceous age, and seems to have been less affected by the great changes of the Pleistocene. . n2 Pacific and Allaiitii' life not Cf|U."'' 1 in later tinu-s, ' and \vlii(di s]»eaks urc'onltMnpoi'ani'ily rallici- than d' what has been t(;nncd honiotaxis. Wo may ])aiiso hero for a moment to notice some of tlie crtecU of Atlanlie urowtii on modern geog-rapliy. il lias ^iven U8 laiiiu'ed and hi-oivcn slioi-es com|)osc'(l of ojcj roeks in the north, and ncwei- lormalions ami sofier featui-os to- ward the south, it lias givrn us marn-inal mountain I'id^'cs and intci'nal plateaus on both sides of the sea. It has ])ro- duced certain curious antl hy no means accidental corres- pondences of the eastern and western sides. Thus the solid I)asis on which tiie Hiitish Ulands stand nuiy be compared with Newfoundland and Lal)rador, the Mn^li'-h Channel with the (iulfof St. I.awrence, the Bay of Biscay with the liay of Maine, Spain with the pi'ojection of the Amei'ican bind at Cape Ilatteras, the Mcditei-ranean with the t cntii'ely I'n to the life reshold with d innniitabic. with googi-a- iuniniei-s and jcfion of the hose remark- former, and noction with -leod at first I changes of vely modern •y, perpetual Tournal Gcolo- ustraliau Fos- 33 summer reigned ns fur north as the middle of rrrconland, and (hat in the Pleistocene, the Arctic cold advanced until an almost ])ercnnial winter ])revailed half way to the e([nalor. It is no wonder that nearly cvoi-y cause available in the lieavens and the earth has been invoked to account for these usiounding facts. It will, I hope, meet with the approval of j'oiir veteran glaciologist J)r. Crosskey if, neglecting most of these theo- retical views, 1 venture to invite your attention in con- nection with tiiis question chiefly to the old Lyellian doc- trine of the modification of climate by geographical changes. Let us, at least, consider how much these are able to ac- count for. The ocean is a gi-eat equalizer of extremes of temperature. It does this by its great capacity ibr heat, and by its cooling and heating power when jjassing from tlu^ solid into the liquid and gaseous state-;, and the I'overse. It also acts by its mobility, its currents serving to convey heat to great distances or to cool the air by the movement of cool icy Avaters. The land, ou the other hand, cools or warms rapidly, and can tiansnnt its influence to a distance only by ihe winds, and the inlluence so ti-ansmitled is rather in the nature of a disturbing than of an equalizing cause. It fol- lows that any change in the disiril)iition of land and w iter must affect climate, more especially if it changes the char- actor oi" course of the ocean currents.' At the present time, the North Atlantic ])i'esen(8 some very peculiar and in some i-espects exceptional features, which ate jnost instructive with rcfci'ence to its ])ast his*)ry. '^fho gieat internal plateau of the American continent is now dry land; the pas>age aci-oss Central America betvveen the Atlantic and Pacific is blocked; the Atlantic opens \e\y widely to the north ; the high mass of (Jrecniand towers in its northern pai-t. The effects are that the gi-eat equatorial curi'cnt, running aci-oss from Africa and embayed in the (Julf of Mexico, is thrown noi'thward and eastward in the ' Von Wu'ickofT has very stronixly put those principles in u Review of Croll's recent book. C/um(/. i-'old An-tic ciiirt'iit iVo'o tlio jxtlar seas is (lirowii to (ho wcshvai'd. and iiiiis dnwn i'vnm (Jri'onlaiid ])ast tlie AmerU'aii sliorc' Tin' pilnt cliart lor .luno of tlii> year shows vast ticlds of diil't iii- on ihc wostorn side of (ho A thin tic as fa r son I h as the hil il ndc (,f |0.-' So far. tiu'rcfoiv, (he (i lacial a_no in that iiai'l of tho A I hint ic still extends : and this at a time when, on the eastern si(leof the Oi'can, tho cultiiio of coi'oals loacdios in Xoiway iioyond the Arctic Cifcje. Lot us iniprn'c* iido some of llie delaiU of lh('s(> l)honomona. Tho warm wa(er (lirown inio the Xorlli Atlantic not oidy iiM'reascs tho (otnperatni-e of its whole waters, hut ^'ivos an oxeoptionally milsiippo>e (ha( a subsidence of land in tropical Americii were to allow the equatorial current to pass throUi;'li into the I'aci lie. The elfoot would at oiu'O he to le luce tho lempei'alui'o ol'Xoruay and Britain (o that of (i recudand and Lahradoi- at pie-ent. while (lie la(tor countries would (liemsid\-es hecome coldei-. T'lie noi'lhern ice, drifting;- down into the Atlantic, would not, as now, he nu'lteil rapidly hy the wai'ut water whicdi il meets in (he (iulf Stream. Much laii;'er (juaiiliiic^ of il would Tcniain undissolvt'd in summer, and lhn> an accumulation ot' permantMit ice would take ]>laco, aloni;' (he Amei'icaii coast at first, but ])i'obably at leni;lli even on (he Mnrcpean side. This would still fiirOier chill thealmosphei'o, ^daeiers wouKl bo established on all the mnnntains of (eni|)erale I'aii'opc and America,-' (ho sninniei- would he kepi eoid by meltiiit;- ' I may rpfer liere to the admirable expositions of thespelK^ftsby tlm late Or. rarpentor, in bispajiers on the resnltsof tlie expl|)i'. ( >ii tilt" \\v |M)l;i!' seas is 'rom (IrrciiliiiKl I'or .Iiiiic of lliU () far. tluToloiv, ill cxtciiils : and llu.' Orcaii, the oiiil tlic Ari-tic (lolaiU of (1h's(> itlantic not only MS, Imt givos an irope. i^till I lie I'li'iiN, and llio •i4's. wIi'k li <'i'0('p .'. in llu' lat it lido till llii' sno\v> ot' Is siippo>(j that a MC lo allow the icilif. Thectle'ct ol' Norway and I p;x'-(Mit. while no coldci'. I'lie (', would not, as \\ liicdi il inocls io ol' it would accuinulaliMn ot' \iuei'ican coast I'aii'i.poan side. . i;-lac'it'rs wouUl njicrali! JMirope cool jiy inidliuij; ol' tll(^S(M'll'<'ptsl\v il' the. cxpinratioii.s is ahoiit 1"_'" al)ove iclow the averivge, ( icoand snow, and, at 'onulli. all l-lastoin Atni'i'ica and l*]uro]io mi^ht hecomo uninhaiiilahlo, excopt l»y aictic animals and plants, as t'ai' south as perhaps II) ' of noith lat i hide. Thiw would he simply a icliiin of tlni (ilaciul ago. I havo assumed only (Uio geoifra|)hical (haiiye; l)Ut otherand inoi-e complete (dian/^^es of suhsidencc^ and elevation mii;hl tal|)()se an o])po>iti' case. The hii;li jihUeau of (Irconhuul might siih^ide or lie reduced in heigiit, and the North Atlantic might he (dosed. At the samo time, the interior ])lain ol" Ameiica Uiight l)ede|)i'essed, so that, as wo know to have heen the ease in the Cretaceous j)eri()(l, the warm waters of the Mexican (Julf would circulate as far north as the i)asins of the present great American laUes. In those circumstances thoro would he an imiiionse diminution of tjie sources of floating ice, and a cori-espondingly vast inci'caso in the surface of warn\ water. The etUbcts would bo to enable a temjiorato flora to sub-ist in (Jreenland, and to bring all the j>re>ent temperate regions of Kurope and America into a condition of siih-ti'opical verdure. It is only necessary to atld that we Unow that vicissitudes not dissimilar Irom those above slietehcd, havo actually occurred in compai'alively recent geological times, to enable us to perceive that we can dispense with all other causes of chiinge of climate, thcuigh ailmitting that some of them may have occupied a secontlary place.' This will give us, ii^ dealing with the distribution of life, the great advantageof not being tied up to definite astronomical cycles of ghuiation, whicli may not alwayn suit the geological facts, and of correlating elevation and .subsidence of the land with changes of climate atl'octing living beings. It will, however, be necessary, as Wallace well insists, that wo .shall hold to that degice of fixity of the continents in their po.sition, notwithstanding ' INIore especially, the injrenious and elaborate arguments of Croll deserve consideration; and, tliou^di I cannot agrca with him in this main thesis, I gladly acknowledge the great utility of the work he has done. 86 the siromcrc;oncos and cmergonccs (hoy have oxpericnccd, to which I have already adverted. Sii- CMiarU^s Lyell, inoi-o than forty years ai^o, pnblisliod in Ids ' Pi-inciples of Geo- lo<>;y' two imaginary ma|>s whicd) iliiistrate the extreme etrects of various disti ilnition of land .md n'ater. In one, all the continental masses ai-o grouped around the equator. In the other, they arc all placed around tiio poles, leaving an open equatoi'ial ocean. In the one case, the whole of the land and its iidiabitiints would enjoy a ]iei'petual summer, and scarcely any ice could exist in the sea. In the other, the whole of the land would he subjected to an Ai'clic climate, and it would give off immense quantities of ice to cool the ocean. But Lyell did not suppose that any such distri- bution as that i-epreseuted in his maps had actually occur- red, though this su]iposilion has been sometimes atti'ibuted to him. lie mei'ely put what ho I'egarded as an extreme caso to illusti'ate what might occur nnder conditions less exaggei'atcd. Sir Charles, like other thoughtful geologists, was well aware of the genei'al tixilyof tin' areas of the con- tinents, though Avith great modilications in the matter of submergence and of land conditions. The union, indeed, of these two great ])riiicii)les of lixity and diversity of the continents lies at the foinidation of theoretical geology. We can now more pi'ocisely indicate this than was pos- sible when Lyell produced his ' I'l'inciples," and ran repro- duce the conditi(Mis of our continents in even the more an- cient pei-iods of theii- hisioiy. Some examples may be taken fi'om the histoiy of tiie American continent, which is more simple in its arrangements than the double continent of Kurop-asia. We may select the early Devonian or Lrian period, in which the magniticeni floi-a of that age — the earliest coi-tainly known to us — made its a])peai-aiu'e. Ima- gine the whole intei'ior ])lain of Noi'ih America submerged, BO that the continent is reduced to two stri|)s on the east and west, connected by a belt of I.aurentian land on the north. In the great ^Lediterranean sea thus jii'oduced, the tepid water of the e;|Uatoi'ial current circulated, and it Hwarmed with corals, of whicdi we know no Ic-s than one hundred ami lifty species, and with other forms of life appro- 3Y ive oxpericncod, [irlos Lyoll, more •iiK'iplos of Gco- Mte (ho extreme 'iitoi'. Fn one, all the equatoi-. In )()lo.s, leaviiii^ an Llie whole of the I'petual siunmci", ii. In the other, .n Ai'ctie elimate, I' ice to cool the any such distri- 1 actually occnr- jtinies at(i'il)uted I as an extreme ' conditions less !;htful i!;eolo^ists, ai-eas of the con- II the matter of union, indeed, of diversity of the ical geology. s than was ])0s- and can repro- ■en the more an- es may he taken I, which is more jle continent of I'onian or l^^rian 1' that age — the )poai'ance. Ima- M'ica submerged, ■ips on the east ian land on the IS produced, the j'cuiated, and it lo le^s than ono •m« of life appro- ■i priate to wai-m seas. On the islands and coasts of this sea was inti'oduced the I'^rian tlo.-a, appeai'ing tirst in the north, and with that vitality and colonizing i)0\voi', of which, as Hooker has well shown, the Scandinavian tiora is the best modern tyi)e, spreading itself to (ho south. ' A very simi- lar distribution of land and water in the Cretaceous age gave a wai-ni and eipiable elimate in those portions of Noi-th America not ^ubmel■g•ed, and coincided with the appearance of the multitude of broad-leaved trees of modern types in- troduced in the early and middle Cretaceous, and which prepared the way ibr the mammalian life of the Eocene. We may take a still later instance from the second con- tinental j)eri()d of the later Pleistocene or eaidy ^Modern, when there wonl(i seem to. have been a partial or entii'e clo- sure of the North Atlantic against the Arctic ice, and wide extensions seaward of the Kui-opcan and Amei-ican land, with possibly considerable tracts of land in the vicinity of the equator, while the Me literranean and the (lulf of Mexi- co were deei) inland lakes.- The ellect of such conditions on the (dimales of the northern hemisphere must have been prodigious, and their investigation is rendeied all the more interesting because it would seem that this continental pe- riod of the ])o t-(rlacial age was that in which man made his tir■^t aei|uaintance with the oasts of the Atlantic, and possibly made his way across its waters. We have in Amei'ica ancient ))oi-iods of cold as well as of .varmth. I have elsewhere refe/re I to the boulder con- glomerates of the lluronian, of the Cambrian and Ordo- vician, of (he Millstono-grit pei-iod of the Carboniferous and of the early Permian; but would not venture to attirm that either of these periods wa- comparable in its cold with the later glacial age, still less with that imaginary age of con- tinental glaciation assumed by certain of the moi e extreme ' An I have elsewiiere endeavoured to show (Rep rt on Silurian (uul DtVhhidi) J'ldiilii nf CdiHold), a warn^ clinuite in the Arctic rejiion seems to have allbrdcd tlio necessary conditions for the ^a-eat colonisiiij; (lorus of all trcoloi^ncal iH'riods. (Jray had previously ilUistratod the same fad in the case of tlic mure modern lioras. - Dawkius, I'opiiUir Science Moullilu, iSl'o. 38 theorists/ Those ancient conpilomcratcs wcie pvohably prodiued by floaliniii; ice, and this at periods when in areas not very remote, temperate floras and faunas could flourish. The ghicial periods of oui- old continent occuri-od in times when the surface of the suijmerged land was opened up to the northern currents, dril'tini;' over it mud and sand and stones, and i-enderini;; nugatoiy, in so far at least as the bottom of the sea was concerned, the effects of the super- ficial warm streams. Some of these beds are also jieculiar to the eastern margin of the continent, and indicate ice-drift along the Atlantic coast in the same manner as at pi-escut, while conditions of greater warmth existed in (he interior. Even in the more recent (rlacial age, wdiile the mountains were covered with snow and the lowlands submerged under a sea laden with ice, there w^cre interior ti'acts in somewhat high latitudes of America in which hardy forest trees and herbaceous plants flourished abundantly; and these wei'O by no means exceptional ' inter-glacial ' ]ieriods. Thus we can show that while from the remote Iluronian period to the Tcrtiaiy, the American land occupied the same ])osition as at present, and while its changes were merely changes of relative 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 gi'catest (rhicial jjci'iod, whii h is best known to us, and is more immediately connected with the early history of man and the modern animals, it may be projier to make u few general statements bearing on the relative imp irtanco 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 tiio greater masses of floating ice are proiucal at the seaward exti'omities of land glaciers, and that the heavy field-ice of the Arctic I'cgions is not so mneli a result of the direct freez- ing of tlio suifaceof the sea as of the accumulation of snow precipitated on ihe frozen surface. In ica>oning on the ' Notes on PoM-Pliocenc of Canada- Hicks, Prt'Cambrian Glaciers, Geol, Mag., 1880. 39 wore prol)ably s when in ai-oas lis could flourish, currcd in times as opened up to d and sand and at least as the ts of the supor- ire also peculiar inoninij;' on the 'Jambrian Glaciers, extent of ice action, and especially of o;laciei's in the Pleis- tocene ago, ii is iieces^^ary to keej) this full in view. Now in tlie formati >n of glaciei-s at ]>"esont — and it would seem also in any I'oncoivabic former state of th "lli—it is necessary that extensive evaporation should con piro with gi'oat con- densati nof watei- ill thosolid form. Such conditionscxist in mountainous regions sufficiently near to the sea, as in Grrcen- land, Norway, the Alps, and the Himalayas; but they do not exist in low arctic lands like Siberia or Grinnol-land, nor in inland mountains. It follows that land glaciatloii has narrow limits, and that we canno'. assume the possibility of great confluent or continental glaciers C(;voring the interior of wide tracts of land. No imaginable increase of cold could render this possible, inasmuch as there could not lie a siilficient influx of va]) lur to i)roiluce the nocessaiy condensation ; and the greatei' the eukl, the less would be the evapoiation. On the other hantl, any increase of heat would be felt moi-e rajiidly in the thawing and evaporation of land ice and snow than on the surface of the >ea. Applying these very simj)lo geographical truths to the North Atlantic continents, it is ea>y to perceive that no amount of retrigeralion cuuld produce a continental tilacier, because there could not bo suiliciont eva])oration and pioci- })itation to atford the necessary snow in the interior. The case of (iroenland is often ivfoi'rod to, but this is the ca-o of a high massof eold land with sea, most!}- (i])en, on both sides of it, i;iving, therefoie, the conditions mcjst fasorablo to pre- einilation of snow. If (iroenland were less elevated, or if there were dry plains around it, the case would bo quite diflorcnt, as Naivs has well shown b^^ his observations on the summoi' verdure of (irinnel-land, which, in the immediate vicinii}' <>f North (ii-cenland, pre-onts veiy diU'erent condi- tions as to glacialion ami climate.' If the plains were sub- moi""'et u\' Norway, sand con-titutes a considerable ])art of the bottom material. Soundings and drcdgings olf (ireat Britain, and also otl' the American coast, have shown that fragments of stone referable to Arctic lands ai'c abundantly strewn ovei' the bottom along certain lines, and the Antarctic (•ontineet. othcwise almost uidcnown, makes its presence fell to the dredge liy the abumlant masses of crystalline rock, ilrilted tar fi'om it to the north. These are not altogether new discoveries. I had infened many years ago, from stones taken U]) by the hooksof fisher- men on *die l)ank> of Newfoundland, that I'ockv material from the north is droppi'(l on these 'banl0 lbs., was taken up from 1,;>40 fathoms, and in the Arctic current, 100 miles tVom land, was a stony deposit, some stones being glac ated. Among these were smoky quartz, (puirtzite, lime- stone, dolomite, mica schist, and serj)entine; also ])urticles of monoclinic and trie liiuc felspar, liornblende, aUgite. mag- netite, mica and glauconite, the latter no doubt formed in the sea-bottom, the othei's drifted from Eozoic and Paheozoic formations to the north.' A retnarkalde fact in this connection is that the groat depths of the sea areas impassable to tlie majoi'ity of marine animals as the land it-elf. According to Murray, while twelve of the Challenger's di'edgiiigs, taken in depths gi'cater than 2,000 fathoms, gave 92 species, mostly new to .science, a similar number of drcilgings in shallower water neai' the land, gave no less than 1.000 species. [lence ai'ises another aii])arent paratlo.K relating to the di>tribution of organic beings. While at tii'st sight it might seem that the chances of wide distribution are exceptiontdly great for marine sjiecies, this is not so. E.Kcej)! in the case of those which enjoy a pei'iod of free locomotion wdien 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 ilcanic islands may Jjfi'ect connections which, though only vol ' Natijs on Poxl- Pliocene nf Canada, 1S72. - Goxral Report, ' Challew/er' Expulhion. 4t temporary, may affonl opportunity for land animals and plants to pass nvin-. With retbi'once to the transmission oj' livini:; l)oini;;s aoross tho Atlantic, we liavo bot'oi-o u-; the i-enrirkaljlo lUct that IVoin the C imhi-ian ago onwards thcr(5 wei'o, on tho two sides of tho oooan, many spouies of inveidehralo animals which, wore cither identical or so closely allii' 1 as to he p )ssib[y varietal foi'ms.' In like manner, the cai'ly plants of ihe Upper Silurian, Devonian, and Carboniferous, present manyidu'nti- cal species, but this identity becon\es loss marked in the vo- getationof tho more modern limes. Kven in the latter, how- ever, there are remarkable connections between tho floras of oceanic islanls and the c )nfinents, which establish this conclusively'. Thus tho Bermudas, altogether recent islands, have been stocke 1 by tho agency chiefly of the ocean cui-rents and of bird>, with nearly 15!) species of continental plants, and the facts collected by Ilelmsloy as to the pi-escnt facili- ties of transmission, along with tho cvi lenco all'ordo 1 l)y older oceanic islands which have been receiving animal anil vegetable colonists for longer p^M-io U, go fir to sb )W that, time i)cing given, (he sea actually affords facilities f)r tho migration of the inhabitants of tho land, comparable with those of continuous continents. In so far as plants are concoi'nod, it is to be observed that the eaidy foi'osts were hirgely composed of cryptogamous plants, and the spores of theso in modern times have jii'oved capalde of transmission for great distances. In considering this, wo cannot ful to conclmle that the union ol' simp'o cryptogamous fructification with arboreal stems of high coir ple.Kity, so well illintratiNl by Di-. Williamson, had a direct relation to the necessity for a rapid and wide distri- bution of theso ancient trees. It seems also certain that ' See Davidson's }fnno{/rapli'^ oi> Bmchiopodx ; Etheridjzo, Adihcas to Gcologicnl Socii'tji of London; Wo xlward, Addrix/^ lo GcologiMs'' Ai^aocMt'ion; also liarrande's SpccxU i\fL'in'>ir>t on (he Bnirhiojiod'^, Cipha- ls of ^ whic'li, woro ■^ibly varietal I'lo Upper "laMyidoiiti- t as now hap])t'iis with the Arctic flora; and when tlu'se wire displaced by colder ])ei'iods, they marched southward along both sides of the sea on the mountain chains. The same remark api)lics to northern forms of marine invertebrate-;, which are much more widely distributed in longitude than those further south. The lato Mr. (Iwyn JettVeys, in one of his laiest communications to this Asso- ciation, stated that o-i ])oi- cent, of the shallow-water mol- lusks of New iMigland and Canada arc also European, and of the deep-sea forms. '.',0 out of 3.'); thesis last, of course, enjoying greater facilities for migration than those which h: ve to travel .■^lowly along the shallows of the coast in order to cross the ocean and settle themselves on both sides. Many of these animals, like the common mussel and sand clam, ai'O old settlers which came over in the ricislo- tene j)eri<)(.l, or even earlier. Others, like the common periwiidvle, seem to have been slowly extending themselves in modcjn times, jierhajis even b^'lhe agency of man. The oldei' immigiants may possibly have taken advantage of lines of coast now submergetl, or of Avarm periods, when they could ci-eep around the Arctic shores. Mr. Herbert Carpcntei' and other naturalists employed on the Challenger collections have made similar statements n'specting other marine invertebi'ates, as, for instance, the l^cliinoderms, of which the deep-sea ciinoids present many common species, and my own collections prove that many of the shallow- water foims are common. Dall and Whiteaves- have shown that some mollusks and Echinoderms are common even to the Atlantic and Pacific C(xists of North America; a remarlcable fact, testifying at once to the fixity of these See paper by the author on Pahoo/oic Khizocarps, Chicago Tmm 18SG. ' Dall, Rqwft on Alaska ; Whiteaves, Tmn?. It S. C, 46 I spocios and to tlio nianncM- In wliich ficy liavo been ablo to lake a(lvanlaj)ecially vertebrates. I do not know that any paheozoic insects or land snails oi- millipede"* of Kurope and America are speciti- cally identical, and of the nume.-ous species of batrachians of the Carbi)niferou.s and reptiles of the Mesozoic all seem to bo tlistinct 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 ap]»earing on the two sides of the Atlantic ; but oven then the species seem dilt'erent, except in the case of a few noj-thei'n forms. Some of the longci'dive(l molUisk's of the Atlantic furnish suggestions which remarkably illustrate tho biological as])cct of those (|uestions. Our familiar friend the oyster ih one of these. The first k'nown oysters ajipear in the (!ar- bonifoi-ous in Belgium and in the (United States of Ameidea. In the Carboniferous and Permian the}" are few and small, and they do not culminate till the Cretaceous, in which there are no less than ninety-one so-called species in Amer- ica alone ; but some of the lai-gest known species arc found in the Rocei^e. The oyster, though an inhabitant of shal- low water, and very limitedly locomotive when young, has r 1 41 •' Ih'cm :iI)Io to '1K> of (ho spo- it'iieo Jiiul (ho 'oiiiolivc |)o\v- 'onns not pro- issod lhl'01|n-h '" to I'cniai'k "t'omotioM in otlioi's may i at (i.-ispc' a !', <>!• whalo- <<> a whale '•'"I probably I"' noi'lh of etl ill vain. y plaiit.s and ■sides of I he '' *^'>l)Orially ic insectH or I aie speciti- bati'aehians :<)ii' all seora ppoars to be ill the later IS thehor.se, two .sides of m ditforent, ntie furnish bioloifioal ho oyster is in the ('ar- )f i\Tnorioa. and small, I, in which s in A mor- i are found nt of shal- K-oung, has ( survived all (lie chani^'cs siiico tlio Carboniferous a^e and has spretul itself over the whole northern hemisphere.' I have collecto I fossil oysters in the Cretaceous clays ol' the coulees of Western Cansida, in (ho Lias sliales of I'ln;;"- laiid. in the Koceno and Cretaceous bods of (ho Alps, ot' Enypt, of the lied Sea coas(, of Judea, and the heights of Lebanon, lOvei-y where untl in all formations tlioy present forms whi(di are so variable and yot so similar that ono ini,i;-ht suppose all the so-c-allod species to bo mere vai'ioties. Did the oyster originate separately on the two sides of the Atlantic, or did it ci'oss over so promiill}' that its appear- ance seems to be identical on the two sides? Are all the oysters of a common ancestry, or did the causes, whatever they were, whitdi introduced (ho oyster in tlio Carboiiifei - ous act ovei- aii'ain in later ])criods? Who can (ell? This is one of the cases wlioi'e causation and development — the two scientitit' factors whitdi coiisiitute the basis of what is vaguely called evolution — cannot easily be isolated. I would recommend to tlioso biobtgists who discuss (lieso questions (o addic( tliemselvos (o the oystoi'. This familiar mollusk has successdilly pursuetl its coui'so and has over- come all its enemies, from the tla(-(oo(lied selachians of (he Carboniterous to the o^ystei -dredgers of (he ])i'esent day, has varied almost iiidcliiiitely, and yo( has continued to be an oystei', unless indeed it nuu' at certain portions of its career have (empoi'ai'ily assumed (he guise of a (Jiypha'a oi" an Kxogyra. The history of such an animal deserves (o be (riiced with care, and much curious informadon i'es[)ec(- iiig it will be found in (he report which \ have cited. liut in these res|)ec(s (he oystci' is merely an example ol' many forms. Similar considerations apply to all those Pliocene and Pleistocene mollusks which are toiuid in the raised sea bottoms of Noi'way and Scotland, on the top of Mod Tryfaon in Wales, and at similar great heights on the hills of America, many ol' which can be traced back to early Tertiary times, and can be found to have extended themselves over all (he seas of the northern hemisphci-e. They apply in like manner to ihe ferns, the conifers, and ' White, liqioii U.S. GcoL Survei/, 1882-83. 48 the nn^ios|)CMmH, innny ot wliifli wo can now follow with- out even sped lie c'h;in,i;"o to th»i I'loceno unci (/lotuccoiiH. Tlioy ill! Mhow tliat tho t'orniH of living things ju-o more 8tiil)lo thiin tho hmdrt and sons in whicli liioy live. IT wo woio to adopt sonic of tho inodoi-n ideas of ovohitioii wo inii^ht out tho (Jordian UnoL by su|)pi)sinir that, as lilco cauHos ju'oduco liUo otlecti!*, thoso typos of lift' havo origin- ated more than once in gooioiific'al liino, and nood not he genetically oonnoctoil with oaidi othor. Mat while ovolu- tionistH ropudiato such a?i a|)))iication of their docti'ino, how- ever natural and rational, it would sootn that natures still more sh'ongly rc|Midiatcs i(, and will not allow us to assume more than one oi-igin foi' one s|H'ci(>s. Thus the groat (jues- tion of goograjjliical distrihution remains in all its force, and, hy still another of our geological jiaradoxes, mountains become ephemeral things in comparison with Iho delicate hci'hago which covers them, and seas are in their present extent but of yesterday, when tompai-ed with the miinite and tbeble organisms that creep on their sands or swim in their waters. The question remains : Has the Atlantic achieved its des- tiny and finished its course, or are there other changes in stoi'o for it in the fuluro? Tho earth's erust is now thicker and stronger than civoi- before, and its great ribs of crushed and folded rock are more firm and rigid than in any pre- vious period. The stupendous volcatiic [)henomona mani- fested in Me\\\vv haml, thai after the long period (»f quiescence which has elapsed, thoi-e may be anew MOttlement of the ocean-bi'd, a(coni)>anieil with foldings of (he crust, es|i(>cially on the western sid«' ot the Atlantic, I [Kissihiy with renewed volcanic activity on its eastern largln. In either case, a long time relatively to our lim- ited human chronology may intervc^ne before the occurrence of any marked cliange. On the whole, tln' e\|iorience of the past would load us to ex))ect movements and. eruptive discharges in the Pacific ratlior than in the Atlantic area. It is therefore not unlikely that (ho Atlantic may remain undistui'hod, iiidess secondarily and indirectly, until after the I'acitic area shall have attained to a greatei- degree of <|uiescence thai: a( |)resont. Hut this sid)ject is one too much involved in uncer(ainty to warran( us in following it farther. In the meantime ihe Atlantic is to us a practicall}' pcr- anent ocean, varying only in its tides, its currents, and winds, whi(di science has already reduc(Ml to definite laws, so that we can use if w(! cannot regulate them. It is ours to take advantage of this |)recious time of quietude, and to extend the blessings of science and of oui- (Miristian civilisation from shore toshoi'e initil there shall be no more sea, not in the sense of that final ing to be the emblem ot unrest and disturb- ance, and the cause of isolation. I must now close this addi'css with a shoi't statement of some general truths which I have had in view in diiccting your attention to thcgeological development of the Atlantic. Wo cannot, 1 think, consider the topics to which 1 huvv re- ferred without perceiving that the history of ncean and con- tinent is an exam])le of progressive design, quite as much as that of living beings. Nor can we fail to see that, while in some imixirtant directions we have penetrated the gi'cat secret of nature, in i-oference to the general plan and stiaic- lui'c of the earth and its wi.ters, and the chann-es tbriuigh which they have passed, we have still very much (o learn, and perhaps (piite as much, to unleai-n, and that the fiituie 50 holds out to us ;iii(l (u our sucoos^ois Iiiu'lier, ;;i jukUm'. and oloarei- conceptions than those lo whicdi wo havcyol allaiiicd. The vastness and tlic niiglit of ocean and the manner in which it cherishes (he feoblesi and most fVa,i;-ile heinn-s, aiili;-s, alil<(! (t^Ili^ hand, and - ; but its tcacli- ler its oi-igin and ;ii made to build till- same time, a and land.