Excerpt from Bibliography of Petroleum and Allied Substances in 1918 This bulletin is the fourth in the series of petroleum bibliographies being published by the Bureau of Mines, the three preceding, Bulle tins 149, 165, and 180, being compilations for the years 1916, and 1917, respectively. In this bulletin the same general plan has been followed in arranging the references, but a few changes and additions have been made in the classification, the more important changes being in the classes Geology and Origin and Refining and Refineries. During the year German periodicals were not available, and, as in the bibliography for 1917, references to articles in foreign journals that were not available have been taken from other sources and credit given to those sources. 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.