26 ANNUAL OF SCIENTIFIC DISCOVERY. 



SUBMARINE TUNNEL BETWEEN. ENGLAND AND FRANCE. 



M. Favre, a distinguished French engineer, has recently brought before the 

 public an extraordinary plan for constructing a submarine tunnel under the 

 channel from France to England ; and what is no less extraordinary, the en- 

 terprise finds supporters, and may be considered as seriously entered upon. 

 The length of the proposed tunnel will be about 184- miles in length, to which 

 must 1)0 added about 14- mile that will run under the shore on each side in 

 order to give the necessary gradual ascent from the tunnel to the surface of 

 the earth. The distance between the top of the arch of the tunnel will be 

 less than 27J yards, so that all danger of the ocean breaking through will 

 be avoided by this enormous thickness of what may be called the wall of 

 the tunnel. This tunnel will be lined with a double arch, the first of granite 

 and of impermeable cement, the second of thin iron plates pierced like a 

 colander with small holes, so that the slightest leakage will be instantly 

 discovered. Through this tunnel it is intended that an atmospheric railroad 

 shall be established, thereby avoiding the smoke consequent on the use of the 

 ordinary locomotive, by which the transit from end to end will be performed 

 in 27 minutes. The natural objection which arises to the practicability of 

 this stupendous work is the difficulty of getting rid of the earth and stone 

 quarried out of the bowels of the subterranean chamber. In the ordinary 

 course of engineering, every barrow-load of earth would have to be brought 

 to one of the mouths of the tunnel, which operation would consume so much 

 time and labor as to add enormously to the expenses. This difficulty M. 

 Favre proposes to surmount by sinking along the course of the tunnel what 

 he calls "Maritime Wells," which will divide this subterranean gallery into 

 sections of about 11,000 yards each in length. By these wells all the encum- 

 bering earth will be thrown into the sea, forming islands about the wells 

 themselves, and so strengthening them. These w'ells will serve the purpose 

 of ventilating the tunnel. The cost of the whole is estimated in round num- 

 bers at 100,000,000f., or $20,000,000, and the cost of each yard will be 

 2,695f., or $539. The soundings that have been made in the English Channel, 

 show that the soil is very favorable to such an undertaking. At a certain 

 depth freestone has been found, so that the vault of the tunnel will be formed 

 of a stone impermeable to water, and capable of sustaining, in a thickness of 

 27 yards, an enormous weight. 



The estimates of the produce of this submarine railway, are based on the 

 supposition that 200,000 passengers now travel backward and forward be- 

 tween France and England at the present day. Of course this number 

 would be increased by the facilities ottered by the submarine railway. France 

 now consumes 80,000,000 of metrical quintals of pit coal, 8,000,000 of which 

 is furnished by England, the remainder by Belgium and Prussia. As the su- 

 perior facility for transport would enable England to supply much of this coal 

 now brought from those countries, the Company calculate that their transport 

 of coal will amount at least to 10,000,000 of tons, which will yield a profit 

 for transport of 10,000,000 of francs yearly for this branch of commerce 



