THE CHANNEL TUNNEL. 407 



before by Sir John Hawksbaw. Using an apparatus of the kind already- 

 mentioned, they succeeded in bringing up a great number of specimens 

 of the rocks forming the sea-bed. These soundings confirmed, in all 

 material points, the old survey. In addition, owing to the great number 

 of soundings that were taken, and to the number of specimens from the 

 bottom that could be identified, it became possible to plot, with some 

 accuracy, the junction of the lower chalk and gault from shore to shore, 

 except for a short distance where those beds pass beneath the sands of 

 the Vai-ne. In addition to the marine survey, a second boring was made 

 at Sangatte, and the results of this work — done in 1875-6 — were published 

 in 1875-7, in the form of reports, with maps and sections. Since then 

 the French Company — acting under the advice of M. Lavalley and M. 

 Raoul Duval — have sunk two shafts a little to the west of Sangatte, and 

 have driven some short headings, in different directions, through the 

 lower beds of the lower chalk, and they are now driving two longer 

 headings by machinery. This is being done for the purpose of defining 

 the position of the gault and lower beds of chalk. 



The researches by the French Company have as yet brought no very 

 novel facts to light, such as to disturb the main conclusions which had 

 been previously arrived at in this country, but they have made our know- 

 ledge more definite in several particulars. Their survey shows that there 

 is no break in the line of the outcrop of the gault, such as would be 

 caused by any large fault. It attempts to define the position of the 

 outcrop of the various divisions of the chalk. The position of these 

 outcrops, on the plan accompanying the French Report (1877), indi- 

 cates a considerable depression in the chalk beds, extending along and 

 not far from the English coasts. Mr. Topley, of the Geological Survey 

 of England, who reported to the Channel Tunnel Company, in 1878, on 

 the French investigations, inclines to think that the view of the French 

 geologists, with regard to the existence of such a depression, is correct. 

 He thinks, moreover, that we may take the position of the outcrop of 

 the gault, as it is shown by them, as being, for all practical purposes, 

 accurate. It diSers from that suggested by Mr. Day ; but the marine 

 survey made for Sir John Hawkshaw had already shown that the chalk 

 probably extended near the English coast much further to the west than 

 Mr. Day had ahown it. We must remember that Mr. Day, in laying 

 down the position of the beds across the Channel, had no other data than 

 he could procure from a study of them on the two coasts. 



Since 1880 the South Eastern Railway Company has been carrying 

 on expei'imental works between Folkestone and Dover. It has sunk 

 two shafts, one near Abbot's Clifi" and one near Shakespeare Clifl". A third 

 shaft is being sunk to the east of Shakespeare Clifi". Headings have been 

 driven from the first two shafts, in directions more or less parallel with 

 the cliff, in the lower beds of grey chalk. 



The above account is a brief summary of the geological work done up 

 to the present time in connection with the Channel Tunnel question. 



As English and French geologists do not employ the same terms in 

 describing the principal divisions of the chalk, I have given a comparative 

 table, showing the divisions recognised in the two countries (see p. 419). 



Before leaving the geological part of the question, I will refer briefly 

 to the information that is available, and may be of use in discussing the 

 question of the tunnel, but which has been collected by geologists, not 

 for that purpose, but in furtherance of their own science. Early in this 



