This volume is dedicated to 
GEORGE M. LIST 
whose wise guidance, kindly encouragement and untiring 
support in administrative ways made possible the final ac- 
complishment of this endeavor. 
The publication of this work has been assisted materially by 
generous contributions by 
JULIUS HYMAN AND COMPANY 
and 
HERCULES POWDER COMPANY 
THOMAS SAY FOUNDATION COMMITTEE: 
S. W. Frost, Treasurer J. J. Davis, Edztor 
R. S. USINGER R. G. SCHMIEDER 
C. D. MICHENER T. H. HUBBELL 
PRINTED BY 
THE A. B. HIRSCHFELD PRESS 
DENVER, COLORADO 
