ILLUSTRATIONS.
| 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.)