A CHAT WITH PROF. COPE — CONTINUED. 365 



The yellow chalk is too soft in many places for build- 

 ings of large size, but will answer well for those of 

 moderate size. It is rather harder at Fort Hays, as 

 I had occasion to observe at their quarry. That 

 quarried at Fort Wallace does not appear to harden 

 by exposure ; the walls of the hospital, noted by Le- 

 conte on his visit, remained in 1871 as soft as they 

 were in 1867. A few worthless beds of bituminous 

 shale were observed in Eastern Colorado. , 



The only traces of Glacial Action in the line ex- 

 plored were seen near Topeka. South of the town 

 are several large, erratic masses of pink and bloody 

 quartz, whose surfaces are so polished as to appear 

 as though vitrified. They were transported, perhaps, 

 from the Azoic area near Lake Superior. 



20 



