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Excerpt from Mining and Scientific Press, Vol. 124: January to March, 1922 In 1890 the output of ore per man-day was certainly less than a ton. Today I have not the data for an accu rate statement. Hut I believe the output per man-day is probably ten times as great. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.