300 D. F. Lincoln — Glaciation of Finger-Lake, etc. 



village in several directions, with very moderate grades. In 

 the direction of the lake the valley-sides become lower, and 

 the valley itself disappears, debouching upon the lake side at 

 an imaginary plane in mid-air. From this point the lake-side 

 descends smoothly and rapidly, while the stream, with many 

 cascades, falls 500 feet in two miles. 



If these valleys, or any of them, had a preglacial existence, 

 and a rational connection with the lake valley, it would seem 

 necessary to suppose that the bed of the latter then stood at 

 an elevation 800 (?) feet higher than at present. If they 

 drained away from the lake, they would soon have been, cut 

 down by robber-streams falling into the Seneca valley. The 

 present Chemung river valley, which would be the southerly 

 exit, is 1200 feet higher than Seneca valley floor. 



The trough of the present lake runs straight south from 

 Watkins to the open valley about Elmira, 22 miles distant. 

 The present bottom of the lake is 1,000 feet below the river at 

 Elmira ; a discrepancy which may be harmonized by either of 

 two hypotheses, — glacial erosion of the lake bed, and filling of the 

 valley at Elmira with overwash from the moraine. That the 

 truth is a composite of both, seems very probable. 



The belief that the lakes are deeply gouged by ice is con- 

 sistent with the fact that their depth (in the case of the two 

 largest) is much the greatest in the southern third. Con- 

 sidered relatively to the glacial movement, this is the down- 

 ward part, and the fact agrees with Geikie's statements 

 regarding the rock- cut lochs of western Scotland, which form 

 basins, deepest toward their outlet. The section of Seneca 

 lake along its axis is like that of an elongated tablespoon, 

 pointed to the north. But until we know more about the 

 depth of alluvial and drift deposit at the ends of the lakes, 

 this consideration may be waived. It is nearly certain, how- 

 ever, that the lake bed is not more than 300 feet deep at 

 Geneva where the apparent depth is 40 feet. 



The direction of preglacial drainage may perhaps be inferred 

 from the considerable and continuous slope of the land toward 

 Lake Ontario. The height of land between this slope and 

 that toward the Susquehanna system is near the south ends of 

 the lakes, and it does not seem necessary to suppose that it 

 was formerly placed much farther to the north. Such valleys 

 as Seneca may have had their divide near the southern ends 

 of the present lakes. A number of streams seem to have 

 run southward across the divide ; of which Ivenka lake, and 

 much of the distribution of the valleys about Canaudaigua 

 and Owasco lakes, offer strong suggestions. 



Few borings have been made north of the lakes, and it is 

 not advantageous to speculate upon a possible outlet for the 



