Report issued by the U.S. Bureau of Mines discussing the annual report over the research and technology of coal during 1941. As stated in the foreword, "these investigations increase our fund of exact knowledge on the properties and composition of American coals and lead to better methods in mining, preparing, storing, and utilizing coal" (p. 4). This report includes tables, illustrations, photographs, and a map.

Preface: The author of this paper gives a thorough description of a complex of very unusual igneous rocks and associated hydrothermal deposits.