1 Sixteenth Annual Report of the United States Geological Survey, Part 4, Mineral Resources of the United States, 1894. pg. 436 footnote: To Mr. William A. Raborg, of the United States Geological Survey, I am especially indebted for the intelligence and unremitting zeal with which he has cooperated in the difficult work of securing and tabulating the statistics of this report.

It is almost unnecessary to state that the statistical data of this report are obtained by direct individual correspondence with the stone producers of the United States. To the thousands of quarrymen who have courteously and promptly replied to the inquiries addressed to them in connection with this and former reports, my grateful acknowledgements are due. The feeling of cooperation shown by quarrymen in contributing to the value of the report by their replies, and the interest which they have always shown in the published results, make the duty of distributing among them copies of this article gratifying one.

In the preparation of this report I have been aided by a number of the technological articles and items which have appeared from time to time in the journal "Stone," and which are elsewhere individually credited, and also by the courteous cooperation of the editor of that journal in calling the attention of stone producers to the importance of replying promptly and fully to the inquiries addressed to them.

In the consideration of the constituent minerals of the granite rocks, I have followed in general, the classifications adopted in the Tenth Census Report on the Building Stones of the United States.