132 Sir Frederick Bramivell [May 19, 



there will be no horses ; and again, when we come to another source 

 of vitiation, viz. that arising from the lamps and candles ordinarily 

 used in such work, we discard such means of illumination and by the 

 electric light and the incandescent lamp get rid of all that difficulty. 

 The preliminary 7-foot heading is now perfectly lighted, without 

 any vitiation of air whatever, by means of this electric light. 



Of course it is obvious, that both during the carrying out the 

 works of the tunnel, and in the permanent tunnel itself, suitable 

 enlargements can be made at intervals to enable sidings to be laid 

 in, depots to be provided, and places for the i^late-layers and others 

 to take refuge in, and I should have said that the approach from the 

 tunnel to the land is to be made by another tunnel having the 

 perfectly workable gradient of 1 in 50. 



I am aware it may be objected, that even assuming the geologists 

 are right in their suggestion — that the chalk marl, or grey chalk, does 

 extend from France to England, and that if excavation can be 

 pursued throughout in the " craie de Rouen " the case as to the 

 facility of execution would be established — there is nothing to show 

 that this chalk may not be fissured in places, and that, as the excava- 

 tion is carried forward, it may not come upon one of these fissures, 

 and so water may flow in. 



To my mind there is the most satisfactory answer to be given 

 to such an objection as this. The grey chalk we find is practically 

 watertight, the fresh water which is in the chalk being in the white 

 chalk above the grey ; this water finds its way into the sea, as we know, 

 at the level of the beach. Moreover there are fissures undoubtedly 

 in the white chalk, and it is extremely probable that through some of 

 such fissures the fresh water is flowing upwards into the sea, the fresh 

 water having come from a greater height than the sea-level, and 

 having therefore a preponderating force, or head, which would enable 

 it to flow out against the pressure of the sea, and in that way 

 such fissures in the white chalk would be kept open notwithstanding 

 they might be at the bottom of the sea, and in that way also, if 

 in the white chalk a well were sunk close to the sea and powerful 

 pumps were put down, drawing more than was supplied to them 

 by the fresh water coming from inland, these pumps would, in all 

 probability, very soon begin to draw in salt water, which would come 

 in the reverse direction to the fresh water, and therefore from the 

 sea through the fissure which had been kept open by the previously 

 outgoing fresh water. But, as I have said, the grey chalk is practically 

 watertight, and the proof of it is not only that which is seen in the 

 trial heading, but farther in the fact that it upholds the water in the 

 white chalk, and that that water goes out into the sea above the 

 grey chalk. It is well known it is idle to sink a well into the grey 

 chalk with the object of obtaining water. This being so, assume 

 that in bygone times, by some agency, I do not know what, a fissure 

 had been made in the grey chalk where it is exposed in the bed of 

 the sea, what would happen to that fissure? no fresh water could flow 



