ELECTRICAL FIRING.

The experiment of simultaneous blasting by electricity has been made

with admitted success. The increased progress in the Central Shaft from

an average of about 18-1/2 to 23 feet per month, demonstrates its

utility, and will undoubtedly insure the continuance of that mode of

firing in preference to the method formerly practised.

Report of the Hoosac Tunnel and Troy and Greenfield Railroad, by the Joint Standing Committee of 1866. · 第 37 / 51 题