00961cam a22002291 4500 gs 42000235 DLC 20260227111348.0 790608r1942uuuuilua s000 0 eng gs 42000235 (OCoLC)5048490 DLC TxCM DLC QE471 .G73 Grim, Ralph E. (Ralph Early), 1902- Modern concepts of clay materials, by Ralph E. Grim. Printed by authority of the state of Illinois. Urbana, Illinois, 1942. 225-275 p. illus. Illinois State Geological Survey Report of investigations no. 80 At head of title: State of Illinois, Dwight H. Green, Governor. Department of Registration and Education, Frank G. Thompson, Director. Division of the State Geological Survey, M. M. Leighton, Chief, Urbana. "Reprinted from the Journal of Geology, vol. I, no. 3, April-May, 1942." Clay. 27820 27820