ABSTRACT
An extremely interesting system of drilling rocks-totally different from that on which the machines the people have just described are constructed-has, within the last few years, been introduced by Messrs. In respect to execution of the work itself, the people consider it proper to drive preliminary driftways or headings under the Channel, the ventilation of which would be accomplished by some of the usual modes adopted in the best coal-mines. Since the completion of the Mont Cenis Tunnel, a still greater piece of rock boring has been begun and finished in the great tunnel of the St. Gothard Railway. It has been suggested that it was largely due to the regular and successful progress of a great piece of rock boring that the Company were enabled to reestablish themselves on a basis that ensured the completion of the whole undertaking.
