Shaler.] 42 [February 6, 



ing to the northward the subglacial stream debouched near the 

 centre of the valley ; from time to time accidents caused the exit 

 of the stream to change its position when the building of the cen- 

 tral Kame was interrupted and the- lateral deposits formed. For 

 a large part of the time while the ice was retreating there were 

 streams breaking out on the borders of the ice sheet that formed 

 the deposits on the flanks of the valley. Finally, when the ice 

 stream in the main valley of the Schroon River disappeared, this 

 lake was drained away, leaving the region much as we now find it. 



That this was the general succession of events in the formation 

 of these Karnes does not, it seems to me, admit of a question. 

 There are however some particular points on which there may well 

 be doubt. The distinct central Kame may not have been altogether 

 deposited in the open water, but may have been partly formed 

 within the arch at the end of the glacier and bared as this arch 

 progressively retreated ; it may, perhaps, owe its extreme sharp- 

 ness and regularity of form to this cause ; although it seems to me 

 that it would have been possible to form it in the open water. The 

 lateral deposits of table and ridge drift may be in some part due 

 to the washing of glacial waste from the steep hill-sides into the 

 border of the lake rather than to any lateral streams, as before 

 suggested, but the main conclusion that the central ridge and the 

 other Karnes were formed beneath a sheet of water by the retreat- 

 ing ice at the close of the glacial period seems thoroughly proven. 

 The extreme regularity of the ridge, the absence of any evidence 

 that portions of it were bodily thrust forward by the advancing ice 

 are conclusive evidence that the progress of retreat of the glacier 

 must have been singularly measured and uniform in its action ; any 

 readvance would have led to the crumpling of the ridge into a con- 

 fused mass ; any sudden retreat would have left long breaks in the 

 deposit. All the evidence goes to show that the process of retreat 

 was carried on with singular uniformity. 



There are evidences of similar glacial lakes in other parts of 

 the southern Adirondacks, but these do not as far as I have been 

 able to find, exhibit the important facts proved by that of Chester- 

 ton. One of these Kame hills lies in and about the village of War- 

 ren, a few miles north of Chester. At that point it is clear that 

 for a time the drainage that now goes to the Hudson was turned 

 to the eastward over the col and down the ravine in which lies 



