Excerpt from Directory of American Cement Industries The figures for imported Portland and for domestic Portland are corrected for the amounts re-exported and exported, respectively, for the years 1901 to 1905. The amount exported previous to that date was small and may be neglected without very appreciable error. De ginning with 1901, the figures show the actual consumption in the United States. Puzzolan was reported with domestic Portland cement prior to 1899, and was very small in amount. Portland cement made from slag is included in the figures for Portland cement and not in those for puzzolan. The data in this table are shown graphically in the accompanying diagram. The vertical ordinate represent the per centages of each cement used in a year, computed on the basis of the total amount of the four classes used during the year, and the diagram represents these percentages for each year from 1880 to 1905. 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.