218 



THE CANADIAN NATURALIST. 



[Vol. X. 



x\u excellent series of souudings can be studied in a line nearly 

 northward from Putneyville, N. Y. : 



Ficfl, 

 Section of Lake Ontario from Foint PeterLic/ht, Ontario, toIhitneyvil[^,KFi 



JE^ Peter. Distanre r^n tiles. J*utntrp^lA 



From this table it will be seen that in a distance of less than 

 two miles the slope of the escarpment is the difference between 

 582 and 24:6 feet, or .336 feet as actually recorded. At Hamilton, 

 the Niagara escarpment is only .388 feet above the lake, which is 

 two miles distant, whilst the present slope at Thorold is spread 

 over nearly twice that distance. That this escarpment is not 

 local is easily seen. For a distance of over forty miles, from 

 near Oswego westward, it plunges down 300 feet or more in a 

 breadth varying from less than two to three miles. Eastward 

 and westward of this portion of the lake this submerged escarp- 

 ment can be traced for nearly one hundred miles, but with the 

 portion deeper than the 70-iathom contour having more gradual 

 soundings, as the base of the hills either originally had a more 

 gradual slope, or the hike in its western extension has subse- 

 quently been filled with more silt. 



Althoutrh we have not soundinirs made verv close together, 

 yet the admirable work of the United States Lake Survey is more 

 than sufficient to prove the existence of a continuous escarpment 

 -which has an important bearing on the Preglacial geography of the 



