246 CHANNEL TUNNEL. [1873-74. 



on the North Sea and Arctic voyages of the Griper ; 

 while Dr Hooker furnished the details of evidence 

 obtained on the voyages of the Erebus and Terror in 

 Antarctic regions. 



The materials and references for any memoir on 

 which he happened to be engaged were carried to 

 London in winter, a great part of which was spent 

 with his wife at 21 Park Crescent, the hospitable home 

 of Mr Charles Falconer, the uncle of Mrs Prestwich. 

 This house was always open to them, and a lengthened 

 winter visit was regarded as a matter of course. 



The date on which a paper was read at the Institution 

 of Civil Engineers, " On the Geological Conditions 

 affecting the Construction of a Tunnel between Eng- 

 land and France," was December 1873. It appeared in 

 the Proceedings of the Institution for 1874. Prest- 

 wich' s knowledge of the strata on both English and 

 French coasts made the writing an easy task. The 

 map, sections, and soundings are given with the utmost 

 clearness and completeness, and the reading of his 

 paper gave rise to an animated discussion, which was 

 resumed at the next meeting, and was continued 

 throughout the evening, several leading engineers as 

 well as geologists taking part. 



After reviewing other strata through which a tunnel 

 might be possible, Prestwich, in summing up, remarked 

 that " the great mass of the Palaeozoic rocks, so pro- 

 tected by impermeable overlying strata, is of such great 

 dimensions, and so compact, and holds its range so 

 independently of the more irregular range of the 

 Secondary strata, that it offers the conditions most 

 favourable for the secure construction of a submarine 

 tunnel ; and that such strata can be worked in safety, 

 and for considerable distances, under great bodies of 



