68 MEETING, MONDAY, APRIL 4. 



mine forms the backbone of Cape Cod, of the Elizabeth 

 Islands, and of Long Island. Professors Cook and 

 Smock, about the same time, traced its course across New 

 Jersey. Somewhat earlier, Professors Whittlesey, Win- 

 chell, Chamberlain, and Irving had identified it in the 

 "kettle range" of Wisconsin. 



This moraine is a line of hills from 100 to 300 feet high 

 running at ri<jht angles to the direction of the ice flow 



O O 3 



and of the kames, is composed of both stratified and uu- 

 stratifiecl material, contains scratched pebbles, and usually 

 has angular boulders of great size upon its surface. Ket- 

 tle holes are likewise abundant along its course and fre- 



O 



qnently of great size. 



During the past two years, Mr. Upham has traced a 

 similar line of hills in a loop, following down the lake 

 region in Minnesota to Minneapolis, thence to the vicinity 

 of Des Moines in Iowa. There it bends to the north-west, 

 crossing the Minnesota line near the south-west corner of 

 the state and continuing as the Coteau des Prairies in Da- 

 kota. The upper part of the Minnesota river is midway 

 between the eastern and the western line of this loop. 

 The distance from one side to another is about seventy 

 miles. 



It is evident from a glance at this map that during the 

 closing part of the glacial period all the drainage which 

 now empties into Hudson Bay poured down through Lake 

 Traverse and the Minnesota river into the Mississippi. 

 This is also proved directly by the size of the Minnesota 

 valley and the extent of the gravel deposits on either side 

 of it. At the same time, the waters of the St. Lawrence 

 were obstructed by the ice to the north, and poured 

 mainly into the Mississippi through two south-western 

 outlets, one from Lake Michigan through Illinois, the 

 other from Lake Erie through the Maumee and the Wa- 



