Dt ANNUAL REPORT 
should cater to the demand for white or colored cement mixtures which 
is constantly growing. In all such colored mixtures the color 
should be stable and should not injure the cement. In this manner a 
demand for higher priced cements answering definite purposes could be 
built up. 
The writer realizes full well the many shortcomings of this report, 
but hopes that this departure from the usual work on cement manufacture 
may in some measure be justified. It is very gratifying to be able to 
record parallel with the mechanical development of the American indus- 
try an increasing activity in the field of research which has already given 
us an honorable position among the world’s investigators in this field. 
In the preparation of this volume the writer wishes to acknowledge 
gratefully the assistance rendered him by Mr. S. V. Peppel, B. Sc., author 
of a report on lime sand brick and the limestone resources of Ohio, and 
Mr. Samuel Torrey Orton, B. Sc., who was an efficient helper during the 
summer of 1902. For illustrations and electrotypes acknowledgment is 
due to the Castalia Portland Cement Co., Castalia, Ohio; Henry S. 
Spackman Engineering Co., Philadelphia, Pa.; The Allis Chalmers Co., 
Chicago, Til’; Tne Kent Mull Coy New York; Phe Hairbanks Scale Co; 
New York; The Williams Pulverizer Co., St. Louis, Mo.; The Bradley 
Pulverizer Co., Boston, Mass., and others. For assistance in preparing 
illustrations the writer 1s indebted to Prof. T. E. French and Mr. Carl B. 
Harrop. | 
