104. w. UPHAM—NIAGARA GORGE AND SAINT DAVIDS CHANNEL. 
Troquois, and the probable conditions of the erosion of this part of the 
gorge, will be considered further on in their relation to the Saint Davids 
channel. 
THE WHIRLPOOL 
In the huge caldron of the Whirlpool the waters of the river, coming 
in from the southeast, sweep around continually to the left, bearing many 
logs and other floating objects, while a part of the surface water on the 
right of the entering rapids, with a deep undertow, pours forth to the 
northeast, making a right angle with the course of entrance. The mini- 
mum and maximum diameters of the pool are about 1,100 and 1,800 feet, 
and its depth is estimated by Gilbert to be about 150 eek 
THE WHIRLPOOL RAPIDS 
Along a distance of one mile, from the railway bridges to the Whirl- 
pool, the river rushes madly in most majestic rapids, having a descent of 
70 feet, from 350 to 280 feet above the sea. Its width is reduced for three- 
fourths of a mile to about 400 feet, and its depth, according to Gilbert’s 
computations, is about 30 feet. 
FROM THE RAPIDS TO THE FALLS 
In the two miles next to the falls the river, varying there from 500 feet 
to nearly 1,000 feet in width, has a smooth and gentle current, which 
becomes strong only in approaching the head of the rapids, the total 
descent in these 2 miles being about 38 feet. The foot of the falls is thus 
353 feet above the sea, and the crest of the American falls is about 517 feet, 
and of the Horseshoe or Canadian falls 510 to 512 feet above the sea. In 
half a mile and four-fifths of a mile, respectively, above the American 
and Horseshoe falls the river descends in mostly shallow rapids about 
55 feet, the smooth current at the head of Goat island having its surface 
570 feet above the sea or 3 feet below the mean level of lake Erie. 
Soundings of the river between the falls and the Whirlpool rapids, 
made in 1875, by the United States Survey of the Northern and North- 
western Lakes, as shown on the detailed map published by this survey 
(to which I am indebted for the foregoing measurements of the widths 
of the river and gorge), range from 107 to 189 feet in mid-channel. The 
maximum depth is opposite Prospect park, and thence a depth of 150 to 
160 feet extends two-thirds of a mile northward. 
Saint Davips CHANNEL 
FROM-SAINT DAVIDS TO THE WHIRLPOOL 
At the little village of Saint Davids, about 22 miles west of Lewiston 
and Queenstown, the Niagara escarpment is broadly indented for a width 
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