Bulletin No 243 Series i A ' Economic Geolo g7» ^ 
bulletin wo. ^4d beries j Bj Descriptive Geology> 50 
DEPARTMENT OF THE INTERIOR 
UNITED STATES GEOLOGICAL SURVEY 
CHARLES D. WALCOTT, Director 
CEMENT MATERIALS AND INDUSTRY 
OF 
THE UNITED STATES 
BY 
EDWIN C. ECKEL 
WASHINGTON 
GOVERNMENT PRINTING OFFICE 
1 9 5 
