Excerpt from Illinois Oil Shales The investigation indicates that the oil shales are more likely to be of future significance than of immediate commercial importance. For many years attention has been directed to oil shales, especially those in Colorado, as potential sources of petroleum. The recent announce ment that the Union Oil Company is erecting a retort near Rifle, Colo., for the processing of an oil shale averaging 30 gallons per ton of recoverable shale oil (oil and Gas Jour., 1955) indicates the increasing significance of oil shales in areas affording a combination of suitable resources and favorable economic conditions. Certain Illinois shales have been known for some time to contain oil (worthen, 1870, p. 105; Ashley, 1917, p. 314 and 319; Winchester, 1919, p. 51; Barrett, 1922; Cox, 1914, p. 26 However, only a relatively few shales were tested, and the resulting data were incomplete or not comparable with current analytical data. 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.