Anthracite coalPrimary CrushingAlva Britt Hooker, Carlton Ernest Brown, Earl Carlton Lane, Ellis S. Hertzog, F. G. Miller, George Stanley Scott, George William Jones, Harold Putnam Greenwald, J. B. Littlefield, Lee Clyde Ilsley, Ludwig Schmidt, Mark Sheppard, Oliver Caldwell Ralston, R. E. Heithecker, W. M. Deaton, Wilbert James Huff, R. G. O'Meara, United States. Bureau of Mines, C. N. Witherow, Clarence John Wilhelm, Earl Jeffries Coggeshall, Ernest J. Gleim, Ernest L. Garton, Harry Clarence Fowler, Helmuth Herman Schrenk, Henry C. Howarth, James R. Cudworth, Robert E. Kennedy, W. B. Berwald, Glen Dale Coe, Harry Mac Cooper, Hilary Breton Brunot
