Coal Carbonizing properties and petrograpbic composition of thick Freeportbed coal from Harmar Mine, Harmarville, Allegheny County, Pa., and effect of blending this coal with Pocahontas no. 3-and no 4-bed coals; by J. D. Davis, D. A. Reynolds, G. C. Sprunk, C. R. Holmes, and J. T. McCartney.