Bulletins. 511. Carbonizing properties, eastern Kentucky coals from Elkhorn no. 1, Elkhorn no. 2, Leatherwood, and Harlan beds [with Publications on survey of carbonizing properties of American coals]; by J. D. Davis, D. A. Reynolds, R. E. Brewer, D. E. Wolfson, B. W. Naugle, W. H. Frederic, and G. W. Birge.