Technical paper: United States Department of the Interior, Bureau of Mines, 211

Technical paper issued by the Bureau of Mines over microscopy of pulverized ores. As stated in the introduction, "this paper, which deals with the study of pulverized ores and the use of the camera lucida in such work, discusses an investigation undertaken at the Seattle and the Golden mining experiment stations of the Bureau of Mines" (p. 3). This paper includes tables, illustrations, and photographs