PAGE. I. Vignette. II. Drilling machine at heading, a photograph taken in Tunnel by Magnesium light, 7,760 feet from West Portal. III. Stereoscopic view. Twelve cans after an explosion, 18 IV. “ “ West End, Hoosac Tunnel, 28 V. “ “ East End, Hoosac Tunnel, 39 VI. “ “ Nitro-Glycerin factory, 43 VII. “ “ “ “ interior of converting room, 46 VIII. “ “ Central shaft, Hoosac Tunnel, 50 IX. Miners ascending “ “ “ “ 58 X. Bursting of can, whilst conveying Nitro-Glycerin, Hoosac Tunnel, 66 XI. Sinking Central Shaft, Hoosac Tunnel, 74 XII. Profile of the Hoosac Mountain, shewing progress January 1, 1872, 80 XIII. "Stopeing out" enlargement, East End, 85 XIV. Driving bench work and dumping from heading, West End, 90 (Photographs taken by L. Daft, operating for Messrs. Thompson & Co., of Albany, the drawings by Assistant Engineers C. O. Wederkinch and G. Lunt, the wood-cuts by Andrew & Son, Boston.) CHAPTER I. Nitro-Glycerin—Introduction of the explosive in New York, San Francisco, Lake Superior, and the Hoosac Tunnel, Massachusetts. Accidents, Reports of Engineers Thos. A. Doane, W. P. Granger and B. D. Frost, of the Manufacturer, Miners’ statement. The city of New York was startled one fine Sunday morning (1865) by an explosion in Greenwich Street, opposite the Wyoming Hotel, the windows of every house within one hundred yards of the entrance to the Wyoming Hotel were shattered, pedestrians were thrown down, and the pavement broken up. A few minutes previous to the explosion, one of the guests in the hotel had been engaged polishing his boots; for this purpose he had drawn from under the counter of the hotel office a small box, on which he had rested his foot; noticing a reddish vapor emanating from there, he drew the attention of the hotel clerk to it, who taking the box in his hands made his way to the front door and threw it into the gutter, whereupon explosion instantly followed.