MECHANICS AND USEFUL ARTS. 101 



TUNNELLING THE ALPS. 



To complete a direct line of railroad communication between Bou- 

 logne, Venice, and Ancona, and consequently between London and 

 the Adriatic, only one obstacle lies in the way. The chain of Mont 

 Cenis and Mont Gene vie, running nearly northeast and southwest, 

 would cross such a line, and present with the elevation of 11,000 feet 

 an insurmountable bar to any direct and continuous railway. The rail- 

 way can with some, difficulty be made to Modane, at the foot of the 

 northern crest of the Graian and Cottian Alps ; but here it must stop, 

 unless a subterranean passage can be found through the mountains, 

 and a project for doing this has been for several years under consider- 

 ation by the Sardinian government. Chevalier Henry Maus has de- 

 voted much study to making the examinations and calculations, and 

 has invented a new boring machine for the purpose of carrying out the 

 plan. He made his report early in 1849, and a commission of engi- 

 neers, army officers, and geologists was appointed to examine into the 

 feasibility of the project. Their report, illustrated by maps, has just 

 been published, and an application for a part of the funds to begin the 

 work will be made forthwith. The tunnel is expected to cost about 

 $ 3,000,000, and may be finished in five years. It will measure 12,290 

 metres, or nearly 7 miles in length. Its greatest height will be 19 

 feet, and its width 25, admitting, of course, of a double line of rail. 

 Its northern entrance is to be at Modane, and the southern entrance at 

 Bardonneche, on the river Mardovine. This latter entrance, being the 

 highest point of the intended line of rail, will be 4,092 feet above the 

 level of the sea, and yet 2,400 feet below the highest or culminating 

 point of the great road, or pass, over the Mont Cenis. It is intended 

 to divide the connecting lines of rail leading to either entrance of the 

 tunnel into eight inclined planes of about 5,000 metres, or 2k English 

 miles each, worked like those at Liege by endless cables and station- 

 ary engines, but in the present case moved by water-power derived 

 from, the torrents. At one point there will be 4,850 feet of mountain, 

 capped with eternal glaciers, overhead. Ventilation must be main- 

 tained by forcing air in and out by mechanical means. 



The newly-invented machine, which it is proposed to use, consists 

 of two large hydraulic wheels, 18 feet in diameter, which move two 

 pulleys (with an endless cable passed twice round them) placed hori- 

 zontally, and of 30 feet diameter, performing 224 revolutions per min- 

 ute. There is also an endless cable connected with the excavating 

 machinery, to move at the rate of 35 feet per second, and a counter- 

 poise or weight to keep the cable in a proper state of tension at the 

 opposite end of the hydraulic wheels, and to travel on a wagon between 

 these and a great well, sunk to receive a corresponding weight at the 

 end of a rope. The machine, once presented to the rock, projects 

 into it simultaneously four horizontal series of sixteen scalpels, work- 

 ing backward and forward, by means of springs cased in, and put in 

 operation by the same water-power. While these are at work, one 

 vertical series on each side works simultaneously up and down, so 

 that together they cut out four blocks on all sides, except on the rock 



9* 



