would be no doubt it might become a thoroughly practical and profitable one. Let us now turn to the great tunnel of the Alps, the completion of which is to be death to the Fell railway.
When M. Medail of Bardonnêche—thirty years ago—pointed out that a shorter tunnel could be constructed beneath the Alps between his village and Modane than at any other place in the Sardinian States having a similar elevation above the level of the sea, neither he, nor any other person, had the least idea how the project could be executed.
The first step was taken by the geologists Signor Sismonda and M. Elie de Beaumont. They pointed out, about twenty years ago, that calcareous schists and quartzite rocks would form a large proportion of the strata through which the tunnel would pass. It takes a miner one hour and a half to two hours to make an ordinary hole for blasting (28 inches deep) in the calcareous schist, and not less than eight hours to make one 20 inches deep in the quartzite.[1] When would the tunnel have been finished if the ordinary processes had been alone employed?
The ordinary processes were clearly unavailable. The tunnel would be not only of prodigious length,[2] but it would have to be constructed without shafts. At no place where a shaft would have been of any use would it have been possible to make one less than 1000 feet deep! If one had been made about midway between the two ends, it would have been no less than 5315 feet deep. "I
- ↑ These are the times actually occupied in the tunnel.
- ↑ The Mont Cenis Tunnel will be 13,364 yards long. The lengths of some of the better known tunnels in England are given below, for the sake of comparison.
The last-named is the longest railway tunnel in England.—Enc. Brit, Art. " Railways."Shakespeare (South-Eastern Railway) 1430 yards 7 shafts. Kilsby (North-Western Railway) 2398 " 2 " Box (Great Western Railway) 3123 " 11 " Woodhead (Man., Sheffield, and Line. Railway) 5300 " ? " The longest canal tunnel in England is the Marsden, on the Huddersfield Canal.—Roney's "Rambles on Railways".
