"' IMAGE EVALUATION TEST TARGET (MT-3) // y. (A 1.0 lifia iiiiiM I.I 11.25 !ff i^ 12.2 a 2.0 1.8 M. mil 1.6 V] <^ /i v: % gb iV iV :\ \ ^9> ^\/#^\ "' CIHM/ICMH Microfiche Series. CIHM/ICMH Collection de microfiches. Canadian Institute for Historical Microreproductions Institut Canadian de microroproductions historiques 1980 Technical Notes / Notes techniques The Institute has attempted to obtain the best original copy available for filming. Physical features of this copy which may alter any of the images in the reproduction are checked below. Q Coloured covers/ Couvertures de couleur L'Institut a microfilm^ le meilleur exemplaire qu'il lui a 6t6 possible de se procurer. Certains d6fauts susceptibles de nuire A la qualitd de la reproduction sont not6s ci-dessous. 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The following diagrams illustrate the method: Les cartes ou les planches trop grandes pour dtre reproduites en un seul clich6 sont filmdes d partir de Tangle supdrieure gauche, de gauche i droite et de haut en bas, en prenant Ie nombre d'images ndcessaire. Le diagramme suivant illustre la mdthode : 1 t 3 1 a . t '. 4 5 6 -m* THE HISTORY OV THE NIAGARA RIVER, By G. K. GILBERT. Extracted from the Sixth Annual Report of the Commissioners op THE State Reservation at Niagara, for the Year 1889. ► ♦♦♦ ^ - ALBAJHT: JA'IES B. LYON, PRINTER. 1890. . \ i c ■7 -, ^ ^ 1' H E HISTORY OF , THE NIAGARA RIVER, By (i. K. G I L BERT. i;.\ii;\(ii;i) I'ltiiM iiii.; Sixiii \NN'i'\r, IiKI'out ov niii ('((Mmissidnkus ok TlIK STATK ltK!|)tli to tlir bottom of the river niuf^es from '200 to fiOO ft-ct. Its wiills are so steep that opportunities for cliinliin;^ up uud down tliem are rare, ami in these walla one may see the geologic strueturo of the plateau. They are eonstitnted of Ixnlded roeks — limestone, shale and sand- stone — lyiiiK nearly horizontal, and a little (ixamination shows that the samii strata occur in the same order on both sides. So evenly are they matched, and so uniform is tlu^ {general width of the f^orj^e, that one might suspec^t, after a hasty examination, the two sides had been cleft asund»M' by some PUitonic agency. But those who havi^ made ;i study of the subjcuit havi eachcd a dif- ferent and bett(!r conclusion — the conclusion that tlie trench was exeavatcul by running water, so that the strata of the two sides are alike because they are parts of continuous sheets, from each of which a narrow strip has hen* been cut. The (!outour of the cataract is subject to change. From time to time blocks of rock break away, falling into the pool below, and new shapes are then given totlm brink over which the water leaps. Many such falls of rock have taken plac since the white man occupied the banks nf the river, and the l)reakiug away of a very large section is still a recent event. By such (d)servation wo are assured that the extent of the gorge is increasing at its end, that it is growing longer, and that the cataract is the cause of its extension. This determination is th(^ first element in the history of the river. A change! is in progress before our eyes. Th(> river's history, like htiman history, is Ix'ing enacted, and from that whicli occurs we can draw inferences concerning what lias occnri'cd and what will occur. We can look forward to the time when the gorge now traversing the fourth })art of the width of the plateau will com- pletely divide it, so that the Niagara will drain Lake Erie to the bottom. We can look back to the time when there was no gorge, but when the water flowed on the top of the plain to its edge, and the Falls of Niagara were at Lewistowu. We may think of the river as laboring at a task — the task of sawing in two tin' plateaii. The task is partly accomplished. When it is done the river will assume some other task. Before it was begun what did the river do ? • t COMMIHHIONKKH 01" TFFK STATE RehEKVATION AT NlAQAIlA. fiS 4 t How can wo answer tliis (lUcstionV Tin- surplus water ilis- cliarj^ed from Lake Erie can not have flowed by tliis course to Lake Ontario without sawing at the j)latfau. IJefore it Ix^^an the cni- tinj^ of thej^'or^e it (litl not flow alonj^ this line. It may have flowed somewhere else, hut if so it did not constitute the Niagara river. The commencement of the cutting of tin* Niagara gorge is the beginning of the history of the Niagara river. We have accom- plisln'd somewhat of our jjurposo if we have discovered that our river Inid a begiiniing. We are so accustonKul to think of streams, and especially large streams, as pernnment, as flowing on forever, that the discovery of a definite; beginning to the life of a great river like the Niagara is important and impressive. Hut that discovery does not stand alone. Indeed, it is but one of a large class of similar facts familiar to students of geology. Let us consider for a moment the ten«leucy of stream histories and the tendency of lake histories. Wherever streams fall ovcm- rocky ledges in ra])ids or in cataracts, their ])ower of erosion is greatly increased by i\w. rapid descent, and they (h'epen their channels. If this process continues long enough, tin; result must be that each sti'eam will degrade its channel through the hard ledges until the descent is no more rapid there than in other parts of its course. It follows that a stream with cascades and water-falls and numerous rapids is laboring at an unfinislKHl task. It is either a young stream, or else nature has recently put obstructions in its path. Again, consider what occurs where a lake interru])ts the course of a stream. The lower part of the stream, the outflow- ing part, by deepening its channel continually tends to drain the lake. The u])per course, the inflowing stream, brings mud and sand with it and deposits them in the still water of tlh lake, thus tending to fill its basin. Thus, by a double process, the streams are laboring to extinguish the lakes that lie in their way, and given sutHcient time, they will accomi)lish this. A stream whose course is interrujited by lakes is either a young stream, or else nature has recently put obstructions in its path. Now if you will study a large map of North America, you will find that the region of the Great Lakes is likewise a region of small lakes. A multitude of lakes, lakelets, ponds and swamps ■"■^r I 64 Sixth Annual Rkpout ok the where ponds once were, cliaracteriiie tlio surface from the Great Lakes northward to the Arctic ocean, and for a distance southward into the Uniti^d States. In tiie same rej^jion water-falls abound, and many streams consist of mere alternations of rapids and pools. Farther south, in the re<5ion beyond the Ohio river, lakes and cataracts are rare. The majority of the streams flow from source to mouth with regulated course, their waters descending at first somewhat steeply, and gradually becoming more nearly level as they proceed. At the south the whole drainage system is mature ; at tlie north it is innnatur<\ At the south it is old ; at the north, vouug. The explanation of this lies in a great geologic event of some- what recent date — the event known as the age of ice. Previous to the ice age our streams may have been as tame and orderly as those of the Southern States, and we have no evidence that there were lakes in this region. During the ice age the region of the Great Lakes was somewhat in the condition of Greenland. It was covered by an immeuse sheet of ice and the ice was in motion. In general it moved from north to south. It carried with it whatever lay loose upon the surface. It did more than this, for just as the soft water of a stream, by dragging sand and pebbles over the bottom, wears its channel dee})er, so the plastic ice, holding grains of sand and even large stones in its under surface, dragged these across the underlying rock, and in this way not only scoured and scratched it, but even wore it away. In yet other ways the moving ice mass was analagous to a river. Its motion was perpetual, and its form changed little, but that which moved was continually renewed. As a river is supplied by rain, so the glacier was supplied by snow falling upon regions far to the north. To a certain extent the glacier discharged to the ocean like a river, breaking up into icebergs and floating away ; but its chief discharge was upon the land, through melting. The climate at its southern margin was relatively warm, and into this warm climate the sheet of ice steadily Dushed and w.as as steadily dissolved. Whatever stones and earth were picked up or torn up by the ice, moved with it to its southern margin and fell to the ground as the ice melted. If the position of the ice margin had been perfectly •i Commissioners of the State Eeservation at Niagara. 65 •Jl uniform, its contiauously deposited load might have built a single high wall ; but as the seasons were cold or warm, wet or diy, the ice margin advanc(Hl and retreated with endless variation, iud this led to the deposition of irregular congeries of hills, constitutiug what is known as the " drift deposit." Eventually the warm climate of the south prevailed over the invader born of a cold climate, compelling it to retreat. The motion of the ice current was not reversed, but the front of the glacier was melted more rapidly than it could be renewed, and thus its area was gradually restricted. During the whole period of retrenchment, the deposi- tion of drift proceeded at the margin of the ice, so that the entire area that it formerly occupied is now diversified by irregular sheets and heapings of earth and stone. The ancient configuration of the country was more or less modified by the erosive action of the ice, and it was further modi- fied by the deposits of drift. The destructive and constructive agencies together gave to the land an entirely new system of hills and valleys. When the ice was gone, the rain that fell on the land could no longer follow the old lines of drainage. Some of the old valleys had perhaps been obliterated ; others had been changed so that their descent was in a different direction ; and all were obstructed here and there by the heaps of drift. The waters weie held upon the surface in innumerable lakes, each overflowing at the lowest side of its basin, and thus giving birth to a stream that descended to some other lake. Often the new lines of descent — the new water courses — crossed regions that before had had no streams, and then they were compelled to dig their own channels. Thus it was that the whole water system of a vast region was refashioned, and thus it has come to pass that the streams of this region are young. Like every other stream of the district of the Great Lakes, the Niagara was born during the melting of the ice, and so we may begin our chronicle with the very beginning of the river. If you will again call to mind the features of a general map of the United States and Canada, and consider the direction in which the streams flow, you will perceive that there is a continuous upland, a sort of main divide, separating the basin of the Great Lakes from the basin of the Mississippi. (A part of its course < 66 Sixth Annual Report of the appears as a broken line on the maps in Plates IV and V.) It is not a mountain range. In great pjirt it is a region of lulls. In places it is only the highest part of the plain. But it is nevertheless a continuous upland, else the waters would not be parted along its course. When the ice had its greatest extent, it passed over this upland, so that the waters produced by its melting fell into the Ohio and other tributaries of the Mississippi, as well as into streams that discharged to Delaware and Chesapeake bays. After- ward, when the glacier gradually fell back, there came a time when the ice front lay in the main to the north of the great water- parting, but had not yet receded from the Adirondack mountains, so that the water that flowed from the melting glacier could not escape by way of the St. Lawrence river, but gathered as a lake between the upland divide and the ice front. In fact it formed not one but many lakes, each discharging across the divide by some low pass ; and as the great retreat progressed, these lakes were varied in number and extent, so that their full history is exceedingly complex. The surfaces of these lakes were stirred by the winds, and waves beat upon their shores. In places they washed out the soft drift and carved cliffs ; elsewhere they fashioned spits and bars. These cliffs and spits and other monuments of wave work survive to the present time, and have made it possible to trace out and map certain of the ancient lakes. The work of surveying them is barely begun, but from what is known we may add a chapter to the history of our river. There was a time when one of these lakes occupied the western portion of the basin of Lake Erie, and discharged across the divide at the point where the city of Fort Wayne now stands, running into the Wabash river and thence into the Ohio. The channel of this discharge is so well preserved that its meaning can not be mistaken, and the associated shore- lines have been traced for many miles eastward into titef Ohio, and northward into Michigan. Afterward, this lake found some other point of dis- charge, and a new shore-line was made twenty-five feet lower. Twice again the point of discharge was shifted, and other shore- lines were formed. The last and lowest of the series has been traced eastward across the States of Ohio and Pennsylvania and into western New York, where it fades away in the vicinity of the COMMISaiONERS OF THE StATE RESERVATION AT NIAGARA. 67 town of Carfyville. At each of the stages represented by these four shore-lines, tlie site of the Niagara Avas either buritd beneath the ice or else submerged under the lake bordering the ice. There was no river. The next change in the history of the lakes was a great one. The ice, which had previously occupied nearly the whole of the Ontario basin, so far withdrew as to enable the accumulated water to ilow out by way of the Mohawk valley. The level of discharge was thus suddenly lowered 550 feet, and a large district previously submerged became dry land. Then for the first time Lake Erie and Lake Ontario were separated, and then for the first time the Niagara river carried the surplus water of Lake Erie to Lake Ontario. The waves of the new-born Lake Ontario at once began to carve about its margin a record of its existence. That record is wonder- fully clear, and the special training of the geologist has not been necessary to the recognition of its import. The earliest books of travel in western New York describe the Ridge road, and tell us that the ridge of sand and gravel which it follows was even then ogiii/(Hl by all residents as an ancient beach of the lake.' In the Province of Ontario th(^ beach was examined and described by the groat English geologist, Charles Lyell, during his celebrated journey in America,'- and it afterward received more careful study by Mr. Sandford Fleming,-* and by the geologists of the Canadian Sarv(\y. ' In western New Yf)rk it was traced otit by the great American geologist, James Hall, during his survey of the geology of the fourth district of the State.'' Within a few years more attention has been given to detail. Professor J. W. Spencer has traced the line continuously from the head of the lake at Hamilton ])ast Toronto, Windsor and Grafton to the vicinity of Bellevdle," 1 (!. Scliultz, Jr.: Triivcls on an inlfind voyago * * * jn the years 1807 and 1808, Xcw York IHin, p. hi>. I)e Wilt ('Hilton: Discourwo boforo tlw-J»«\v V(jrk Iliatorieal Sucioty, IHII, p. OS. Fnuiris Hall: Travols in Canada and the United StatdB in IHIO and 1817, Bo:-(ton, IhiH, p nil. •2 Tivn-fis in N'ortli .Vniorifa in tlii« your.s lH\i->. Now York. Ihi.';. Vol. 2, pp. 8(1-87. :i Sanill'oi'd FkMiiini;: N'otus on tlui Davoiiport trravcl drift. Cuiiiidian Journal, Now Sorii'fi, vol. f>. PI I. '.U.-'J."):i. 4 Oeolowifal Survoy of (Janada, roportto inn:), pp. 9H-'.tir). n Natural History of Now York. Ooolouy. Tart IV. pp. ;i4« r.t. ('. (Jonnnuiiicatcd to the Philosophical Sooioty of Washington ; to l)o puhlishod in Vol. 11 of tlu> liullctin of the Socioty. ™HC- 68 Sixth Annual Report op the beyond which point it is hard to follow. Soutli of the lake, I myself have traced it from Hamilton to (^ueeuston and Lewiston ; thence to Rochester, and all abont the eastern end of the basin to Watertown, beyond which point it is again difficult to trace. Southeast of the present margin of Lake Ontario, there was a great bay, extending as far south as Cayuga lake, pnd including the basil; of On(!ida lake, and it was from this bay that the dis- charge took place, the precise point of overflow being tin present site of the city of Rome. )r this predecessor of Lake Ontario Professor Spencer has j^roposed the name of Iroquois. Putting together the results of his survey and of my own, I have been able to prepare a map (PI. II) exhibiting with a fair amount of detail the outline of the old lake. It will be observed that the northeastern portion of the shore is not traced out. In fact it is not traceable. The water w•^s contained on that side by the margin of the glacier, and with the final melting of the ice all record of its shore vanished. The form and extent of Lake Iro(]uois, and the form and extent of each other lake that bordered the ice front, were determined partly by the position of the pass over which the discharge took place and by the contour of the land; but they were also deter- mined to a great extent by the peculiar attitude of the laud. Perhaps a word of general explanation is necessary in speaking of the attitude of the laud. Geologists are prone to talk of eleva tion and subsidence — of the uprising of the earth's crust at one place or at one time, and of its down-sinking at another place or another time. Their language usually seems to imply the rise or fall of an area all together, without any relative displacement of its parts; but you will readily see that, unless a rising or sinking tract is torn asunder from its surroundings, there must be all about it a belt in which the surface assumes an inclined position, or, in other words, where the attitude of the land is changed. If the district whose attitude changes is a lake basin, the change of atti- tude Avill cause a change in the position of the line marked about the slopes of the basin by the water margin, and it may even cause the overflow of the basin to take a new direction. The Oiitai'io basin has been subjected to a very notable change of attitude, and the effect of this change has been to throw the x> 0; s ja I x (/. o i S e *- s « 5" ^ g ^ «■ — * c « ~ e ? 1 E = I ~t « c B "= h) -a " ea tif c u ■o >< •a 2 o M H Commissioners of the State Reservation at Niagara. 69 ancient shore-line out of level. When the shore-line was wrought by the waves, all parts of it must have lain in the same horizontal piano, and had there been no change in the attitudt^ of the ba.siu, every point of the shore-line would now be found at the level of tiie old outlet at Rome. Instead of this, we find that the old gravel spit near Toronto — tlie Davenport ridg(> — is forry feet higlier than the coutemporaniM)us gravel spit on which Lewiston is built ; at Bell nille, Ontario, the old shore is 200 feet higher than at Ilochester, N. Y. ; at Watertown 800 feet higher than at Syracuse ; and the lowest point, in Hamilton, at the head of the lake, is iVliy feet lower than the Jiighest point near Watertown. From these and other measurements we le.aru that the Ontario basin with its new attitude inclines more to the south and west than with the old attitude. The point of discharge remained at Rome as long as the ice was crowded high against the northern side of the Adirondack mountains, but eventually there came a time when the water escaped eastward between the ice and the mountain slope. The line of the St. Lawrence was not at once opened, so that the sub- sidence was only partial. The water was held for short times at various intermediate levels, recorded at the east in a series of faint shore-lines. Owing to the attitutle of the land, these shores are not traceable all about the basin, but pass beneath the present water level at various points. Finally the ice blockade was raised in the St. Lawrence valley, and the ])resent outlet was established. During the period of final retreat the attitude of the land had slowly changed, so that it wjiSj not then so greatly depressed at the north as before ; but it had not yet acquired its present position, and for a time Lake Ontario was smaller than now, its western margin lying lower down on the slope of the basin. An attempt has been made in PI. Ill to exhibit diagramatically the relations of ice dams and basin attitudes to one another and to the river. The various elements are projected, with exaggeration of heights, on a vertical plane running a little west of south, or parallel to the direction of greatest inclination of old water-planes. At N is represented the Niagara escarpment and the associated slope of the lake basin ; at A the Adirondack mountains. R and 70 Sixth Annuax, Report of the T are the passes at Rome and at the Thousand Islands. Succes- sive positions of tlio ico front are marked at I', I- and I'. The strai^h lue numbered 1 represfmtH the level of lake water previous to the origin of the Niaj^ara river; 2 gives the first position of the water level jvfter the estal/lishment of the Home outlet ; and the level graduall}' shifted to 3 ; 4 is the first of the series of teraporaiy water levels when the water escaped between the mountain slojje and thci ice front ; 5 represents the first position of the water level after the occupation of the Thousand Island outlet; and (5, the present level of Lake Ontario. It should b(^ addedparenthetically that the shore of Lake Iroquois as mapped in PI. II is not quite synchronous. Between 2 and 3 of PI. Ill there was a continuous series of water levels, but it was not easy to map any one except the highest. The northern part of the map delineates the margin of water level 2, and the southern part the margin of water level 3. It is easy to see that these various changes contribute to modify the history of the Niagara river. In the beginning, when the cataract was at Lewiston, the margin of Lake Ontario, instead of being seven miles away as now, was only one or two miles distant, and the level of its water was about seventy-five feet higher than at present. The outlet of the lake was at Rome, and while it there continued, there was a progressive change in the attitude of the land, causing the lake to rise at the mouth of the Niagara until it was 125 feet higher than now. It fairly washed the foot of the clitf at Queeuston and Lewiston. Then came a time when the lake fell suddenly through a verticjd distance of 250 feet, and its shore retreated to a position now submerged. Numerous minor oscillations were caused by successive shiftiugs of the point of discharge, and by progressive changes in the attitude of the land, until finally the present outlet was aci^uired, at which time the Niagara river had its greatest length. It then encroached five miles on the modern domain of Lake Ontario, and began a delta where now the lead-line runs out thirty fathoms. While the level of discharge was lower than now, the river had different powers as an erodin, ..gent. The rocks underlying the low plain along the margin of the lake are very soft, and where a river flows across yielding rocks, the depth to which it erodes is 1 a COMMI88IONE11R OF Till". S'lATE RESERVATION AT NueAltA. 71 limitod chiefly by th(» level of its point of (liscluir^o. So when the poiut of |H f > > s p M n O "S? IB a Tk «» <« a tr T m p .- ts >« c 3 VI TT di B a V) f» a • » (S r a '■^ ^ p *4 "! ^ &- i,^ (X s » ^ n p t a p* «^ ■1 •< ts c ^ a »• J5 V 1 -1 ■3 5 D* l: •< «* ^, m* P 3 n p- «*i r^ 1 w o » B "1 , t c' » ct U) tn > SB g ftl •1 p ct- ? D. e -5 s fB '-i UJ ■* ^> S" P ■t ,.,.^ — :~— -t!I,- » c--.. ^•**' -.-"*■■ *' "^*--'*- t *x V\., " '^^^^^&7>-^ ^ i '"'^^J^''''''^^^^^.^ "^ 1 * '''^^^§w$$^y f ■ ^^ ' *"?V^N^^ V ^ J ^"'"""""^ \v§\ \ R^ 0^' ■' '*"•■"" V^^Jo / ^ (^ / '^'^^^'^ l*^^^^ v .'T> ^^ "^ i / J I -._-., b """X ' ""'x^"'>^^T^ / , ,» r" '"*^^^.2u ^^ ^-"Tr^xN/ JCvnXxx^ '*'"' ^ s*> '•''■. •' 'S*-, .-' <^$y^ i^$$i$$/^$^^L/^^• "--^.,.^'\ \ ^^'^l^^^i 1 \ * /v^<\ ' rK\x\\\v^!^s^N!^s^ ^.^7^'-<._ ^5 ^^^^^^^»v "*' W K '^- T-' V '' '>-..-'^~<§T^ \ '^■•••••^ •'* * ''*j'*\^ J \ 'S ^ \ 1 .' J '^X \ ^■^ \ \ , - "^k \ y\ ~%^ \ / *\ »\. J ' — ■ '. li _^_^ f'^''' ' ****"" "x^ ■ 1 1 X ^^^>V^ 1 '■-- -r"^^^^: 1 i 1 ■ — -^ '^i , /' K ' I '^mmmmmmn "v'.f' '"»im.f\,^ Commissioners of the State Reservation at Niagara. 73 dry. The Trent pass is much higher than the Nipissing pass, so that it appears necessary to assume that during the history of the Trent outlet for the upper lakes, the great glacier still occupied the region of Lake Nipissing, preventiag the escape of the water in that direction. The map in PI. V represents the system of lakes and outlets at that time. It is largely theoretic, but I believe its general features consistent with our present knowledge of the facts. Unless I have misunderstood Professor Spencer, Lake Ontario was at high stage in the first part of the epoch of the Trent valley outlet, and was afterward at low stage. I have selected as the date of my map the epoch of the high stage, with the outlet of Ontario at Rome, and have indicated an ice sheet so extensive as to block the way, not only at Lake Nipissing, but at the pass of the Thousand Islands. The d.ite of this map is earlier than the other; it belongs to a time when the northward depression of the land was greater. Lake Erie is represented as less in extent, for its basin in that position would hold less water. Huron and Ontario would likewise be smaller were their waters free to escape over the lowest passes ; but the ice blocks the way, and so their waters are raised to the level of higher passes. Of the contemporaneous relations of the upper lakes we know nothing at present. They are drawn as though commimicating with Lake Huron, but it is ecjually pos- sible that they fell into some other drainage system. Here again the Detroit channel was not in use, and the Niagara river was outlet only for the waters of the Erie basin. Graphic methods are ill adapted to the communication of qualified or indefinite statements. By the aid of a map one can indicate definitely the relation of Albany to other j^laces and things, but he can not say indefinitely that Albany is somewhere in eastern New York, nor can he say, with qualification, that it is probably on the Mohawk river. For this reason I have decided to i3ublish these two maps only after hesitation, l)ecause I should greatly regret to produce the impression that the particular configuration of lakes and outlets here delineated has been actually demon- strated. The facts now at command are suggestive rather than conclusive, and when the subject shall have been fully investigated it is to be expected that the maps representing these epochs will 74 Sixth A>^nual Report of the exhibit uuiteriiil differences from those I have (Ir.iwii. The sole point that I wish to deveh^p at this time is the jjrobability tliat (birinj^ a portion of the history of the Niagara river, its drainage district — that area from which its water was supplied was far less than it is at the present time. There i I'eason to believe that during an epoch which may have been short or long, we can only vaguely conjecture, the Niag-ira was a comparatively small river. The characters of the goige are in general remarkably nnifoi-m from end to end. Its width docs not vary greatly ; its course is flexed but slightly ; its Avails exhibit the same alternation of soft and hard rocks. Lut there is one exceptional point. Midway, its course is abruptly bent at right angles. On the outside of the angle there is an enlargement of the gorge, and this enlarge- ment contains a deep pool, called the Whirlpool. At this jjoint, and on this side only, the material of the wall has an exce])tional character. At every other point there is an alternation of shales, sandstones and limestones, capped above by an unecpial deposit of drift. At this point, limestones, sandstones and shales disap})('ar, and the whole wall is made of drift. Here is a place where the sti'ata that floor the plateau ai'e discontinuous, and must have been discontinuous before the last occupation of the region of the glacier, for the gap is filled by glacial drift. Another physiographic feature was joined to this by Lyell and Hall. They observed that the cliff" limiting the plateau has, in general, a very straight course, with few indentations. Bat at the town of St. Davids, a few miles west of Queenston, a wide flaring gap occurs. This gap is partly filled by drift, and although the glacial nature of the drift was not then understood, it was clearly perceived by those geologists that the drift-filled break marked the position of a line of erosion established before the ])eriod of the drift. Putting together ihe two anomalies, they said that the drift-filled gap at the Whirlpool belonged to the same line ( f ancient erosion with the drift-filled gap at St. Davids. • Their conclusion has been generally accepted by subsequent investigators, but the interpretation of the phenomena was carried little farther until 1 Travfjls in North Aun-ricii. By Cliniies T,y*-ll. Xtnv Yiiik, !H4n. Vol. II, pp. 77-80. >'utural History of New York. Ueolony, I'art IV. liy James Hall, pp. asa-auo. urn itro { Ku:\: m ^mmm h e h •1 to a //], I Commissioners of the State Reservation at Niagara. 75 the subjoot \V!is studiod by Dr. Jalius Pohlmiui. ' He pointed out that the upper course of the ancient {j;or^e C(jukl not have lain outside the modern ^orj^e. If the course of one ^or^e hiy athwart the course of the other, we sliouhl have two breaks in the con- tinuity of the strata, instead of the sinj^le one at the Whirlpool. The upper part of the ancient gori;ether what we have learned of the Niaji;ara history. The river b(^i:;an its existence during the final retreat of the great ice sheet, or, in other words, durin,!j; the series of events that closed the age of ice in Nortli America. If we consider as a geologic period the entire time that has elapsed since the beginning of the age of ice, then the history of the Niagara river covers only a portion of that period. In the judgment of most students of glacial geology, and, I may add, in my own judgment, it covers only a small portion of that period. During the course of its history, the length of the river has sufi:ered some variation by reason of the successive fall and rise of the level of Lake Ontario. It was at first a few miles shorter than now ; then it became suddenly a few miles longer, and its present length was gradually acquired. With the change in the position of its mouth there went a change in the height of its mouth ; and tlu^ rate at which it eroded its channel was att'ected thereby. The influence on the rate of erosion was felt cliiefiy along the lower course of the river, between Lewiston and Fort Niagara. The volume of the river has likewise been inconstant. In early days, when the lakes levied a large tribute on the melting glacier, the Niagara may have been a larger river than now ; but there was a time wlieu the discliarge from the upper lakes avoided the route by Lake Erie, and then the Niagara was a relatively small stream. 1 Proc. A. a. a. S., 36tb MeotiDK (Buffalo), pp. 221-222. ' 76 Sixth Annual Eei'out of the The ^rejit life work of the river has been the dij^j^'in*^ of the }^orge through which it ruuH from tho Ciitaract to Lowistou. The bcgiu- uiug of its lift' was tlif bcginuiug of that task. The length of the gorge is iu some sense a mc^asure of the river's ago. lu the main the material dug has IxM'n hard limestone and sandstone, inter- bedded with a coherent thoiigh softer shale; but for a part of the distance the material was incoherent drift. The geologic ago of tlu; earth — the time during which its surface has been somewhat as now, divided into laud and ocean, subject to endless waste on the land and to endless accumulation of sediment iu the ocean, green with verdure and nourishing the varied forms of animal life — this time is of immense duration. Even the units into which geologists divide it, the periods and epochs of their chronology, are themselves of vast duration. Human history is relatively so short, and its units of (centuries and years are so exceedingly brief, that the two orders of time are hardly commensiirate. Over and over again the attempt has been made to link together the two chronologies, to obtain for the geologic units some satisfactory expression in the units of human history. It can not in fairness be said that all these attempts have failed, for some of them are novel and untested ; but, however successful or unsuccessful they may have been, the interest in the subject remains, and no discussion of the history of the Niagara river would be complete without some allusion to its value as a geologic chronometer. It is true we know but little of the ratio the river epoch bears to the extent of the glacial period, or to any longer geologic unit ; but yet were we able to determine, even approximately, the time consumed by the river in cutting its gorge, we should render less hazy and vague our conception of the order of magnitude of the units of the earth's geologic history. The problem has been attacked by numerous Avriters, and the resulting estimates have ranged from three or four thousand years to three or four million years. The method of reaching a time estimate has been, first, to estimate the present rate of recession — the rate at which the cataract is increasing the length of the gorge ; second, to compute, with '".he aid of this estimate and the known length of the gorge, the time necessary for the entire excavation ; and, third, some rorge :)f the inaiu intor- Df the ch its ocean, tion of ig the rut ion. As aud ii-atiou. uturies line are [IS been for the [human its have owever t in the Sliagara [\\G as a le ratio to any |e, even ting its 111 of the history. Iiucl the Lousand Itirat, to ■lich the [)mpnte, gorge, ll, some Commissioners of the State Resekvation at Niagara. 77 writers have modified their result by giving consideration to various conditiims affecting the rate of erosion during earlier stages of the excavation. The enormous range of the resulting estimates of time has depended chiefly upon the imperfection of data with reference to the present rate of recession of the falls. It is but a few years since measurement of the rate of recession was substituted for bald guessing. This measurement consists in making surveys and maps of the falls at different times, so that the amount of change in the interval between surveys can be ascertained by comparison of the maps. In 1842 Professor Hall made a survey of the outlines of the falls, and he published, for the use of future investigators, not only the map resulting from the survey, but also the bearings taken with the surveying instrumont in determining the principal points of the map.' He likewise left upon the ground a number of well- marked monuments to which future surveys could be referred. Thirty-three years later a second survey was made by the United States Army Engineers, and they added still further to the series of bench vc ks available for future reference. Three years ago. my colleague, Mr. R. S. Woodward, executed a third survey.'* Plate VII exhibits the outline of the crest of the falls, together with the brink of the (dilT in the vicinity of the falls, as determined by Mr. Woodward in 188(), aud also shows a ])art of the same out- line as determined by Professor Hall forty-four years earlier.^ If both were precise, the area included between the two lines would exactly represent the recession of the Horseshoe and American falls in forty-four years, and the retreat of the cliff face at Goat Island in the same time. I regret to say that there is internal evidence pointing to some defect in one or both surveys, for there ai'e some points at which the Woodward outline projects farther towards the gorge than the Hall outline, and yet we can not believe that any additions have been made to the face of the cliff. Never- theless, a critical study, not mersly of these bare lines on the chart, but also of the fuller data in the surveyors' notes, leads to the belief that the rate of recession in the central part of the Horse- 1 Natural HiBtory of New York, Goolof?y, Tart IV, pp. 40-2-40;i. 2 Soionce, Vol. VIII, 188C, p. 205. ;t The poutli side of this chart ia placed iippomiost (iu violation of the conventional rule) so that it may accord with the bird's-eye views. ! t 78 Sixth Annual Report op the shoe Fall is approxiiuutol}' dotermiuecl, niitl tliut. it is Hoiuewhere between four foet Jiutl six foot i^er aniuira. The amount fall«'n away at the sides oi' the Horsoshoii is not well cloteriniued, but this is of less importance, for such falling; away alTects the width of the gorge rather than its length, and it is the length with which we are concerned. The surveys likewise fail to afford any valuable estimate of the rate of retreat of the American Fall, merely telling us that its rale is far less than that of the Horseshoe — a result that might be reached independently by going back in imagination to the time when the two falls were togetiier at the foot of Goat Island, and considering how much greater is the distance through which the Horseshoe Fall has since retreated. The rate of retreat of the central portioii of the Horseshoe is the rate at which the gorge grows loL^;er. Now if we were to divide tlu; entire length of the gorge by the space through which the Horseshoe Fall retreats in a yeai", we might regard the resulting (quotient as expressing the number of years that the falls have been occupied with their work. This is precisely the procedure by which the majority of time estimates have been deduced, but in my judgment it is not defensible. It implies that the rate of retrogression has been uniform, or, more precisely, that the present rate of retrogression does not differ from the averag(^ rate, and this imjjlication is open to serious question, I conceive that future progress in the discussion of the time problem will consist chiefly in determining in what ways the conditions or circumstances that affect the rate of retrogression have varied in past time. In order to discuss intelligently these conditions, it is necessary to understand just what is the process by which the river increases the length of its gorge. There can be no question that the cataract is the efficient engine, but what kind of an engine is it ? What is the principle on which it works ? It has already been stated that the rocks at the falls lie in level layers. The order of succession of the laycns has much to do with the nature of the cataract's work. Above all is a loose sheet of drift, but this yields so readily to the wash of the w'der that we need pay no attention to it at present. Under that is a bed of strong I me where int fallen iued, but ihe width ith which ite of the it its rale iui<^ht be the time t Ishiud, ^h which 3at of the he gorge ^0 by the year, we imber of This is :isti mates ublo. It or, more lot difJ'er > serious on of the ways the agression tly these i process efficient principle 3 in level 3 do with t of drift, we need )f strong PI.ATE VII.- Chart of the CUtr L.nTTt th. hen., „f «.. ^,„„„,, ,,„^.J compiled to show the Recession from IHii to 188G ^'I'u^r/TnTsr Ful/irn'e'^rBt'U'f .r"^' '^'"^ ""' '"^^^^O ^^ ^- ^- state Geol- I COMMIHHIONEKH OF THE StaTE RehEHVATION AT NiAOARA. 79 limeHtoiu\ ^riiis is cuIIchI tlio Niii^'iira linicstono, and its thickuesa is oi^lity feet. IJeiitNith it in u sluilo, calh'd tho Niagara shale, with a thirkneHs of fifty f»M.'t; ami then for thirty-tivo feet there is an alternation of liniestoue, shale and f^andstone, known collfetively as the (Minton ^ronp. This rea(di('s down very nearly to the water's edf^o. Beneath it, and extending* downward for several hnndnnl feet, is a }j;reat bed of soft, sandy shale, interrnpted, so far as wo know, by but a sinj^le inird layer, a sandstone ledf»e, varying in thickness from ten to twenty feet. These are the Mculiua shales and the ^ledina sandstone. Th(! ])r()hl<' in Phiti' VIII indicates that the hard layers pi'ojiu't as shelves or steps, and th t the softer layers are eaten back. I have been led so to draw them by con- siderations of analojj;y oidy, for underneath the center of the great cata.ract no observations have b(>en mudut where the United States Engineers were able to lower their plummet, a half a mile away, a depth was discovered of nearly 200 feet, and I have assumed that the cataract is scouring as deeply now as it scoured at the time when that part of the gorge was dug. It is a matter of direct observation that, from time to time, largo blocks of the upper limestone fall away into the pool, and there seems no escape from the inference that this occurs because the erosion of the shale ^ ^neath deprives the limestones of its support. Just lunv the shale is eroded, and what is the ])art played by the harder layers beneath, are (juestions in regard to which we are much in doubt. In the Cave of the Winds, where one can pass b(uieath and behind one of the thinner segments of the divided fall, the air is tilled with spray and heavier masses of water that perpetually dash against the shale, and though their force in that place does not seem to be violent, it is possible tnat their con- tinual beating is the action that removes the slialy rock. The shale is of the variet}' known as calcareous, aud as its calcareous oleraeut is solul)le, it may be that solution plays its part in the work of undermining. What goes on beneath the water of the pool must be essentially difFereut. The Niagara river carries no sedi- UMJ I . V. U-l ^/ 80 Sixth Annual Report of the ment, and therefore cau not scour its cliaunel in the manner of most rivers, bnt the fra ij z o I- co u 2 < < < mm I if ' u _l < I < ir < < z o a: o u. z o H z J O I'l'liUil.lilil.Mli < Z 5 111 2 z o s c o 8 o it I 0< •jg -'I; | ii| 1 i i n mir^miimnifir / , / Commissioners of the State Reservation at Niagara. 81 above, with beds of softer rock beneath, with the foice of falling water, and possibly, also, with the solvent power of the water. Concerning each of these factors a number of pertinent questions may be asked, questions that should certainly be considered, whether they are answered or not, before any solution of the time problem is regarded as satisfactory. To illustrat(! their pertinence, a few will be propounded. Question 1. Does the limestone vary in constitution in different parts of the gorge ? If its texture or its system of cracks and joints varies, the process of recession may vary in consequence. Question 2. How does the limestone bed vary in thickness in different parts of the gorge V This question is easily answered, for at all points it is well exposed for measurement. Question 3. How is the thickness of the limestone related to the rate of recession? This is more difficult. The dobris from a very thick bed of limestone would oppose great resistance to the cataract and check its work, The di'bris from a very tliin bed would afford small and inefficient pestles for pot-hole action, and might lead to a slow rate of recession. If the thickness now seen at the cataract Avere slightly increased or slightly diminished, it is not at once apparent how the rate of recession wouhl be affected, and yet there might be an important difference. We have seen that the pre-glacial stream whoso channel is betrayed at the Whirlpool, removed the Niagara liinestone through a portion of the gorge, and Question 4 asks : Through what portion of the gorge was the Niagara limestone absent when the Niagara river began its Avork ? Questions. Does the rock section beneath the limestoiio — the shale series Avitli its imbedded harder lavers — does this vary in different parts of the gorge V Question (>. Through wJiat distance Avere the several members of the underlying rock series removed by the action of the pre-glacial stream ? Coming noAv to consider the force of the falling Avater, a little consideration serves to sIioav that the force depends on at least three things : The height through Avbich the Avater falls, the degree of concentration of the stream, and the volume of the river. L«^ 82 Sixth Annual Report of the Tlio height of tlio fall is tlio vortical distance from its crest to the surface of the pool below. Question 7 asks : How has the hei}j;ht of the crest of the fall varied diirin*^ the history of recession '? Question 8. How has the height of the base of the fall varied ? And this involves a subsidiary question, — to what extent has the excavated gorge, as left by the retreating cataract, been refilled, either by the falling in of fragments from the clifts, or by contributions of debris brought by the current? Question 9. What has been the form of the channel at the crest of the fall, from point to point, during the recession? Wherever the channel has been broad, and the water of uniform depth from side to side, the force of the falling water has been applied dis- advantageously ; wherever the channel has been narrow, or has been much deeper in some parts than in others, the force of the water has been a])plied advantageously. There are many ways in which it is possible that the volume of the river was made to differ at early dates from its present volume. During the presence f)f the ice, there was a different climate, and there were different drainage systems. Question 10. During the early history of the river, was the annual rainfall cm which its water su})ply depended greater or less than now ? Question 11. Was the evaporation from the basin at that time greater or less than now ? It is believed that at the present time the Niagara river receives less than half the water that falls upon its basin in rain and snow, the remainder being returned to the air by evaporation from the lakes, from the surface of the land and from vegetation. Question 12. Was the water su})ply increased by ablation? There may have been times Avhen the overla])ping edge of the glacier discharged to the Laurentian basin large bodies of water furnished by the molting of ice that had congealed from the clouds of regions far away. Question 113. Was the drainage area of the river at any time increased through the agency of ice barriers ? Just as the W^innipeg basin was made to send its water to the Mississippi, sf) we can imagine that regions north of the Great Lakes and now tributary I , il ».«-• lie fall ! Commissioners of the State Eeservation at Niagara. 8B to Hudson's bay, had tlioir disoliavge temporarily turued to Lake Superior and Lake Huron. On the other hand, we have seen that the discharge of the whole district of the u])per lakes was for a time turned away from the Niagara river. Therefore, we ask : Question 14 To what extent and for what periods was the volume of the river diminished through the diversion of the discharge of the upper lakes ? Assuming all these questions to be answered one by one, and the variations of different sorts determined, it is still necessary to learn the relations of those variations to each other, and so we ask : Question 15. How have the variations of rock section, the variations of cataract height, the variations of form of channel and the variations of volume been related to one another in point of time? What have been their actual combinations? Question 16. How have the various temporar}' combinations of factors affected the process of retreat and the rate of recession. The tale of questions is not exhausted, but no more are needed if only it has been shown that the subject is not in reality simple, as many have assumed, but highly complex. Some of the ques- tions are, indeed, easily ansAvered. It may be possible to show that others are of small moment. It may even be that careful study of the local features will enable the investigator to infer the process of cataract work at each point from the existing condition of the gorge, and thus relieve him from the necessity of considering such remote (Questions as the nature of glacial climate and the history of glacial retreat. But aftiM' all ])ariug and pruning what remains of the problem will be no bagatelle. It is not to be solved by a few figures on a slate, nor yet by the writing of many essays. It is not to be solved by the cunning discussion of our scant, yet too puzzling knowledge — smoothing away inconvenient doubts with convenient assumptions, and cancelling out, as though compen- satory, terms of unknown value that happen to stand on oj)posite sides of the eipiation. It is a problem of nature, and like other natural prol)lenis demands the patient gathering of many facts, of f:i3ts of many kinds, of categories of facts suggested by the ten- K*"^ i&a H ii i 84 Sixth Annual Report on State Reservation at Niagara. tative theories of to-day, and of new categories of facts to be suggested hy new theories. I have said our problem is but the stepping stone to another problem, tli(! discovery of common units for earth history and human history. The Niagara bridges the cliasm in another way, or more strictly, in another sense, for the term of its life belongs to both histories. The river sprang from a great geologic revolu- tion, the banishment of the dynasty of cold, and so its lifetime is a geologic epoch ; but from first to last man has been the witness of its toil, and so its history is interwoven with the history of man. The human comrade of the river's youth was not, alas, a reporter with a '^ ^te-book, else our present labor would be light. He has even told us little of himself. We only know that on a gravelly beach of Lake Irocpiois, now the Ridge road, he rudely gathered stones to make a hearth, and built a fire ; and the next storm breakers, forcing back the beach, buried and thus preserved, to gratify yet whet our curiosity, hearth, ashes and charred sticks. ' In these Darwinian days, we can not deem primeval the man possessed of the Promethean art of fire, and so his presence on the scene adds zest to the pursuit of the Niagara problem. What- ever the antiquity of the great cataract may be found to be, the antiquity of man is greater. 1 American AnthropoloRist, Vol. II, pp. 173-174. ^1 * Y