16 0 79 26 18 210 8 G 06 1 11 08 Mammoth Vein, 83 feet thick. 信 Coal, 6 7 16 0 10 1 10 23 8 23 18 8 60 4 8 1 10 FIG 1.-Cross-Section of the Second or Middle Coal-field, in FIG. 2.-Section of the Lehigh Valley Coal Co.'s Bore-hole, the vicinity of Shenandoah, Pa. Vol. II-20, Rogers, Profs. R. C. Taylor, W. R. Johnson, J. C. Booth, M. C. Lea, and Dr. Ellet, of samples taken from these beds at Wiconisco shows the specific gravity of their coal to be 1397; their percentage of carbon, 83-30; volatile matter, 10:42; and ash, 6'11. observable in the Middle field, of hard, pure anthracite thirty analyses made by State-Geologist Prof. H. D. at the eastern end, changing gradually to a softer anthracite at the western. It is only at the western ends of the Southern and Middle fields that the lowest coals of the series are found in workable condition. These are classified by some authorities as a single bed, and marked as "A," or the beginning of the series; but in Dauphin and Northumberland counties they are two regular beds, averaging, respectively, 3 and 8 feet in thickness, and yielding a product well known in all anthracite markets as Lykens Valley coal. This coal is soft, easily ignited, and burns freely, but without the smoke and odor of bituminous coal. The average of The analyses by the same authorities of twenty samples of Lehigh coal (hard, white-ash anthracite) average as follows: Specific gravity, 1577; carbon, 89-25; volatile matter, 9'86; ash, 4.20. The following are analyses of anthracite coals from beds in Schuylkill county: Moisture..... Volatile matter.................................................................................................... Ash............................................................. Sulphur. Pounds of water evaporated by 1 lb. coal... 11-12 1.960 1.500 1.480 1.920 Bed. VI. VII. VIII. IX. Average 1.440 1.350 1.200 1.250 1.020 1-457 8-480 1-460 0.530 2-640 1.410 2.970 2:494 88.032 93-502 96.199 89-576 90-986 88-147 89-083 6.330 8.360 1.900 6.250 6.020 7.200 6-701 0.238 0.238 0.021 0.334 0.334 0-663 0-252 100-00 100.00 100-00 100.00 100-00 100-00 100-00 99-987 8-82 10-34 11.00 10.36 10-60 10-40 10-10 11-60 The Ashes Test.-Another method of distinguishing I. Little Tracy, 4ft. 6 in.thick, from Ellangowan colliery. different varieties of anthracite-and a very important II. Big Tracy, Knickerbocker " III. Diamond, 7" 2" 11" 6 66 66 IV. Orchard, 8"10 66 V. Primrose, VI. Mammoth, 37 66 N. Mahanoy 66 VII. Skidmore, VIII. Seven-foot, 7 66 66 W. Shenandoak" one from a commercial point of view-is by the color of the ash, which ranges from a pure white in some specimens to a deep red in others. The Lykens Valley coal, just mentioned, yields a light-red ash. Overlying this are four beds of white ash coal, forming the next or middle number of the series. Then comes a valuable bed of gray-ash, and then a red-ash group. (See fig. 4.) The color is due to the presence of ferric oxide; and this, in turn, is supposed to have been diffused through the air by volcanic action, to be deposited by rain in the forming_coal-beds. Prof. Greene (Coal, its History and Uses, p. 63) traces the coloring of the red sandstones to the same source. The well-known intermittent character of volcanic discharges will perhaps account for the coloring of the lowest coals, the absence of color in the middle series, and the deep tint of the ashes of the upper beds; especially when it is considered that the upper beds are thousands of years younger than the lowest ones, and that, as Prof. Greene points out, volcanic action apt to be most intense when the volcano is about expiring. The commercial importance of the coloringmatter in coal-ashes is due, not so much to its presence or absence as to its furnishing an (apparently acci dental) indication of the grade of the coal. All white ash anthracites are hard and well adapted for use in blast-furnaces and other fires which require intense heat and great resisting power in the fuel. They all contain a high percentage of carbon, with but little ash, and neither crumble nor cake in the hottest fire. The red-ash coals, on the other hand, are softer, crumble |