and the Geology of the Surrounding Country. 115 



with existing facts, appears to me to be, that the ravine of St. 

 Davids was excavated by the power of the waves, aided prob- 

 ably by\a stream, though it may have been a very insignificant 

 one. That this ravine was formed previously to the period of 

 the drift, and that during this time it became filled with the 

 transported materials to such an extent that the stream after- 

 wards was unable to excavate a channel through the mass. 

 Under these circumstances, the water would find an outlet at 

 the lowest point, into the basin of Ontario ; whether that 

 point were over a surface of rock or of drift, and after the 

 channel was once commenced, it would go on deepening, un- 

 less some violent change should alter the configuration of the 

 surface. Now there is no evidence of such a change in the 

 Niagara district, and it seems more rational to conclude that 

 the stream, which may have formerly found its way through 

 the ravine of St. Davids, after the filling up of that channel, 

 took the course by Lewiston, that being the lowest point at 

 which it could find a passage to the lower country on the 

 north. It may be necessary, perhaps, to suppose a depression 

 in this direction before the water would flow there ; and such 

 a depression may have existed from causes in operation previ- 

 ously, or there may have been an indentation in the edge of 

 the terrace at this place, like those farther east, near Lockport. 

 There appears, indeed, strong reason for supposing that there 

 was a depression in the surface at the place where the river 

 now flows, before the deep channel was excavated ; there is a 

 general depreswsion on either side, and a transverse section of 

 the river would present the appearance represented in the an- 

 nexed diagram. 



The recent deposit, forming Goat Island, is upon a surface 

 lower than the top of the rapids, indicating removal of the 



