2 IN AND OUT OF ITHACA. 



scene broke the horror of the glacial epoch. Ice to an 

 extent which the imagination even cannot compass, 

 covered the land reaching down to what in distant fu- 

 ture ages was to be the State of Pennsylvania. It filled 

 all these little valleys, and as it moved slowly, majesti- 

 cally and mercilessly over the country, it ground off 

 sharp corners into rounded curves, it scratched out little 

 irregularities completely, and in places where it stayed 

 longest it dug out the valley to a greater depth. The 

 ice gradually moved off to the north, dropping its debris 

 from its receding edges, and this moraine matter is now 

 plainly visible on the Spencer divide. It yielded a little 

 on the south, but the great glacial mass, like a huge 

 dam, still shut off the outlets of the valleys in the 

 north. Then in that valley which in ages to come was 

 to be filled by Cayuga L,ake, began the action which 

 has resulted in the curious glens and gorges that make 

 our Ithaca so enchanting and bewildering a place. 



As the ice receded the space it left behind was occu- 

 pied by a lake, shut in at the north by the ice-dam. 

 The old water-courses were broken up. The little 

 streams poured into the lake here and there, wherever 

 it happened it seems, and rapidly wore away the soft 

 rock where they chose their channels. The debris from 

 this cutting process was deposited just under water at 

 the mouths of the streams, forming deltas. By and by 

 the ice-dam to the north gave way a little, and the level 

 of the lake was consequently lowered. These deltas 

 then became little terraces, and the streams cut deeper 

 and took down more debris to form other deltas below. 



