Excerpt from Illinois Mineral Industry in 1942 The increased demand on industrial minerals used in the metallurgical industry is particularly noteworthy. Demand for refractory pro-ducts ih creased 23 per cent, silica sand 41 per cent, ground silica 32 per cent, and lime 31 per cent. The production of coal increased 18 per cent in quantity and 24 per cent in value, whereas the output of crude Oil, on the other hand, declined 19 per cent in quantity and 16 per cent in value. Production Of crude oil in Illinois continued to decline from the high level of 1940. The decline of productivity In some Of the larger and older fields of the I.llinois basin, together with the decrease in the size of new pools currently discovered, were the initial cause of the production loss. However, the normal procedure of meeting a strong market demand by more intensified exploration and wildcat drilling was curtailed by the re strictions. Imposed upon the purchase of drilling field equipment and sup plies for the oil-producing industry, and other causes. 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.