LETTER OF TRANSMITTAL 
Department of the Interior, 
United States Geological Survey, 
Washington, D. C, May 11, 190 lp. 
Sir: I have the honor to transmit herewith the manuscript of a 
report on the cement materials and industry of the United States, by 
Edwin C. Eckel, and to recommend its publication as a bulletin. 
This report has been prepared in accordance with the policy of sum- 
marizing existing information concerning one or more of the non- 
metalliferous mineral products each year. It contains, however, an 
exceptionally large proportion of entirely new information. In its 
preparation Mr. Eckel has visited every district in which cement was 
being produced and has examined nearly every plant in operation. 
Information relating to undeveloped deposits of cement materials has 
been obtained by personal examination and from the published and 
unpublished work of other geologists. 
The object has been to treat the subject from the geological rather 
than the technical standpoint, although the technology of cement man- 
ufacture is also discussed with sufficient fullness for the purpose of the 
report. In view of the phenomenally rapid growth of the cement 
industry within recent years, the publication of this report will be 
exceptionally timely, 
Very respectfully, 
C. W. Hayes, 
Geologist in Charge of Geology. 
Hon. Charles D. Walcott, 
Director U. S. Geological Survey. 
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