d iw -m qjo v ~'*' q- ■•„"■'/ -'A, 1 Economic Geology. 39 
Bulletin No. 243 QC Series ( fi ' ^^ Q J^ m 
DEPARTMENT OF THE INTERIOR 
UNITED STATES GEOLOGICAL SURVEY 
CHARLES D. WALCOTT, Director 
CEMENT MATERIALS AND INDUSTRY 
OF 
THE UNITED STATES 
EDWIN C. ECKEL 
WASHINGTON 
GOVERNMENT PRINTING OFFICE 
1905 
