Ventilation by fan, 151; by open furnace, 150; in bituminous mines, 199; principle of, in mines, 97, 148. Von Storch, H. C. L., 65. Wages of miners, 224; computing and payment of, 222; of boys, 213–215; sliding scale for computing, 224. Waste in coal mining, 134; of the coal measures, 28. Water, driving workings toward, 155; in mine, 96; tonnage of, hoisted, 155. Weighing coal, 223. Weiss, Colonel Jacob, 48. Western middle coal field, 33. West Pittston, disaster at, 175. White & Hazard, coal trade of, 62; experiments of, 60. Wilcox, Crandal, 56. Wings in shaft, 91. Woodward breaker, 121. Working pillars, 136. Wright, Joseph, 56. Wurts, William and Maurice, 65. Wyoming coal field, 33. Wyoming valley, discovery of coal in, 45; early coal trade of, 56. Ziegler, Charles W., 188. * * * * * Transcriber’s Notes: ――Text in italics is enclosed by underscores (_italics_). Superscripted characters follow a caret (Fred^k, 11^th) ――Obvious printer’s, punctuation and spelling inaccuracies were silently corrected. ――Archaic and variable spelling has been preserved. ――Variations in hyphenation and compound words have been preserved.