98 Geology and Topography of Western New _— = 
‘to four or six feet, it is underlaid by a very fine zee of olf 
‘horizontally stratified, containing fragments of limestone similar 
to the rock beneath. It appears to belong to the extensive clayey 
2 “deposit, which covers large tracts on the limestone range, and in 
-- which I have never met with any fossil remains ; ae oe! 
may, and probably will hereafter, be detecte 
The extent and power of these counter leasballi which! exca- 
vated the valley of the Niagara, and assisted in cutting down the 
ravine below the falls, remain to be determined, when the laws 
which govern the ebb and flow of tides shall be fully developed, 
- and when the shape of this ancient gulf, at this stage of eleva- 
tion, shall be approximately ascertained. It is well known, that 
the height and violence of tides are materially modified by the 
direction of prevailing winds, by oceanic currents, and by the 
shape of coasts and estuaries. At some places on the coast of 
England, as in the Bristol channel, the tide rises forty-two feet,* 
and in the Bay of Fundy, to the enormous height of from sixty 
to one hundred feet.t As ‘no land which is now less than 575 
feet above tide water, had then emerged from the ocean—uniless 
its rise was less rapid than this region, and the reverse is probably 
tre of the primitive districts—this arm of the sea had ample 
communication with the Atlantic, through the Gulf of St. Law- 
rence, and the valley of the Hudson. At this stage, the primitive 
range in the north of this State, and those in the New England , 
States, were but islands; and it is not improbable, when the rel- ua 
ative levels shall be alegrieioctle that other passes will be found, 
at a less elevation above tide water than Lake Erie. Receiving 
the tidal wave, therefore, through these different channels, which > 
would meet in the vicinity of Lake Ontario, an additional im- 
pulse would be communicated to it, and a tide would probably 
result, little inferior to that at either‘of the places above cited. 
There is another phenomenon connected with tides, which 
ought not to be forgotten. If, as suggested, this strait received a 
powerful tide, it might, when vushing upthe narrow gorge above 
| Lewiston, have produced that kind of tidal wave, called the 
Bore,” which, says Lyell,t “is sometimes produced in a river, 
where a large body of water is made to rise pain in coma 
ee 
ae eficnlegs, Vol. 1, p. 228. 
re 's Birds of America, Vol. 11, p. 448. Also, Ameriean Journal, Vol 
: v, p- 132. Also, Rees's and the American Encyclopedias. : 
* * Lyel's Geology, Vol. 1, p. 274. ana 
: 
