Technical papers. 725. Investigation of lower coal beds in Georges Creek and north part of upper Potomac basins, Allegany and Garrett Counties, Md., reserves, petrograpnic and chemical characteristics of coals, and stratigraphy of area; by Albert L. Toenges, Louis A. Turnbull, Lloyd Williams, H. L. Smith, H. J. O'Donnell, H. M. Cooper, R. F. Abernethy, and Karl M. Waage.