TUNNELS IN GENERAL AND THE ST. GOTHARD IN PAR TICULAR. 667 



•modern Italy, the guide and inspirer of the Five Days of Milan, in 1848, when 

 the unarmed citizens defeated and drove out from their city the entire Austrian 

 army under Radetsky, as early as 1859 insisted on the tunnel through the St. 

 Gothard, in the interests of Italy and Switzerland alike. 



It appears that, fearing injury to their traffic from Paris to Brindisi via the 

 Mont Cenis, the French are now, in consequence of this new tunnel, boring 

 through the Simplon — estimated at eleven and one-half miles in length — and 

 "already there are rumors of schemes to bore through the Tarentaise and the Col 

 du Mont; and even Mont Blanc is threatened with a tunnel," consequent upon 

 the feverish competition likely to arise among the Swiss, German, French and 

 Italian lines. 



Five years ago. La Nature reported that in Spain an inter-continental rail- 

 way company had been formed to carry out the scheme of connecting Europe 

 and Africa by a tunnel under the Straits of Gibraltar, but nothing has been done 

 in the matter. 



But the bold idea of a tunnel under the British Channel will, if carried out, 

 eclipse all former undertakings of this kind. The present '' Channel Company" 

 was formed in 1872; Sir John Hawkshaw, F.R.S., Mr. Brunlees and M. Gamond 

 being appointed engineers. The route finally decided upon places the tunnel on 

 a line extending from a spot between Folkestone and Dover, through the "Old 

 Gray Chalk," to a point between Sangatte and Calais, on the opposite coast. 

 The total length will be thirty-one miles, of which twenty-two will be under the 

 Strait. Shafts are to be sunk on each shore to a depth of about 450 feet below 

 high- water mark ; and drift-ways from the bottom of these, for the draining of the 

 tunnel, which is to begin 200 feet above the driftway. These driftways will be 

 driven from both ends on a down gradient of one in eighty to the junction of the 

 drainage driftway; and then on an up-grade of one in 2,640 to the middle of 

 the Strait. The crown of the tunnel in all parts will be not less than 200 feet 

 below the bed of the Dover Strait. It is hoped that the excavation will be 

 mostly through chalk, in which case comparatively rapid progress will be made. 



It has been estimated that the probable cost of this titanic task will be about 

 $20,000,000; but Sir John Hawkshaw considers it best to double this estimate, 

 in anticipation of greater obstacles which may arise. The preliminary works are . 

 now being prosecuted with great activity. A shaft has been sunk at Sangatte, 

 to the depth of over 100 metres, and the experimental gallery has been commenc- 

 ed, and is to be continued for a kilometre — that is 3,250 feet — under the sea. 

 The raising of the capital for the tunnel itself is, however, still a knotty problem; 

 but if this can be accomplished, so much the better for all parties. As the pas- 

 senger traffic between England and the continent amounts to nearly 400,000 an- 

 nually, and is yearly on the increase, the opening of this marine subway will be 

 of enormous public advantage. 



