Excerpt from Industrial Minerals Produced in Illinois in 1943: Clays and Clay Products, Fluorspar, Sand, Gravel, Silica Sand, Ground Silica, Tripoli, Stone, Cement, Lime, Mineral Wool and Agstone Used in Illinois in 1943 War conditions profoundly affected the production of all industrial min erals in Illinois in 196. Those minerals necessary to the war effort have been produced in constantly increasing amounts, but the general shortage of labor and decreased demand has reduced the production of other industrial minerals in varying degree. 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.