POPULAR SCIENCE MONTHLY. 



Fig. 



]0. — Map of the Whirlpool Eavine. 

 bb^ Position of section (Fig. 11). 



gorge was followed, as most authors absorb the work of others 

 without verifying it throughout. In this matter even the present 

 writer, in the beginning of these investigations (1881), partially- 

 accepted Lyell's idea, but 

 distinctly showed that the 

 buried ravine from the 

 whirlpool was not pre- 

 glacial but probably that 

 of a small interglacial 

 stream, and not that of 

 the Niagara River. Prof. 

 Claypole found rocks in 

 the ravine, and then the 

 writer immediately cor- 

 rected his statements (1887), and later explained the whole his- 

 tory ; but apparently Prof. Gilbert had forgotten these observa- 

 tions and went back to Lyell's views in their entirety. The 

 mistake was easily corrected by going through the ravine, where 

 rocks three hundred feet above the bottom of the river are ex- 

 posed, as shown in Figs. 10 and 11. The exposed rocks along the 

 western side of the ravine show the slope as in section, which is 

 a characteristic form of ancient valleys in contrast to the vertical 

 walls of the caiion (Figs. 6 and 7), while on the eastern side the 

 rocks are covered with drift and landslides, but at the same time 

 demanding sloping walls beneath. Thus the presence of rocks 

 so high in the ravine removes from the calculations of the work 

 of the river the obstructions of early observers, and relegates the 

 hamlet of St. Davids, made famous the world over, to its peaceful 

 repose. 



It is perhaps necessary to explain the form of the whirlpool 

 basin. A moderately shallow valley, now buried, was formed in 

 ancient times by a stream 

 flowing from near the 

 railway bridges, and ex- 

 tending down by way of 

 the buried ravine (which 

 has given so much trou- 

 ble) to join the ancient 

 Tonawanda River a little 

 to the west (see Fig. 5). Most of the capping limestones in the an- 

 cient little ravine near the site of the whirlpool had been removed, 

 leaving at or near the surface only soft, shaly rocks, yet three hun- 

 dred feet above the bottom of the river. Wheti the modern falls 

 had receded so as to reach the edge of the little buried valley, 

 it found the surface occupied by loose materials which for a 

 short distance the river easily swept out, and thus by the cir- 



Fio. 11. — Section across the Whirlpool Ravine: 

 located at bb (Fig. 10). 



