Fig. 6, from “C” coal seam
Fig. 8 X-Ray photograph of a piece of coal taken from “C” coal seam, Lynch, Harlan County, Virginia.
(cropped from border; levels 20 1.00 255; color levels/shadows -20 0 +20)
ex Edward O’Toole. “Dry cleaning of coal by means of tables.” Year Book of the American Iron and Steel Institute 1921 (1922) : 203-234 (comments 232-234)
Harvard copy, digitized June 30, 2008
tags: abstraction; coal; skiagraphy; tables
E. O’Toole