H.D. Ward 1872 (published) Central Shaft, Hoosac Tunnel.
Stereoview Jeffrey Kraus Collection Book plate in: George M. Mowbray, 1872, Tri-Nitro-glycerin, as Applied in the Hoosac Tunnel Submarine Blasting, Etc., (North Adams, Massachusetts: J.T. Robinson), between pp. 50-51
