Chapter 7.82 - Niagara (continued)
Continued from 7.81- and its height from Lake Ontario is 334 feet.
This fall of the whole river is divided, first into the fall of 20 ft. from Lake E. to the rapids - Then a fall of 40 ft. in half a mile at the rapids. At the Falls it plunges at once 164 feet. Then between the base of the Falls and Queenston, 7 miles, it falls 101 feet.”
“If the Falls were formerly at that place, their height was probably twice as great as now. Tho' very likely, this was not one un-interrupted fall. The beds of limestone, shale, etc.dip to the north about 25 ft. a mile -The upward slope of the bed of this river is about 15 ft a mile. Should the Falls have reached 2 miles, at the end of 10,000 years (which they will do, if keep on changing as now,) their height will be 80 ft. The recession would then become more slow, as the base would be of solid limestone."
This is all very curious certainly, and worth thinking about. According to this calculation, the stratum of limestone now at the falls would be about 30 feet. This is plainly to be seen at the path beneath Table Rock. There is the stratum of limestone projecting more than 50 ft. Over your head, supported by a bed of shale which you can with ease pick to pieces with your fingers. One trembles to find so crumbling a support to that immense projection.