1875.] The Channel Tunnel. 499 
under the Channel, the one by M. Thomé de Gamond between 
Eastwear Bay near Folkestone, on the English side, to Cape 
Gris-Nez on the French coast, and the other, which has 
already been referred to, and with which the names of 
Hawkshaw, Brunlees, and Low are associated, from between 
St. Margaret’s Bay, near the South Foreland, to a point be- 
tween Sangatte and Calais. The former of these, it was 
subsequently ascertained, would pass through a number of 
different beds. In mid-channel on this line there are two 
shoals, known as the Varne and the Ridge, which belong to 
the Portland formation, the same as that to which the cliffs 
at Cape Gris-Nez belongs, and under it are the Kimmeridge 
Beds. ‘These rocks dip to the north-west, and it is supposed 
that somewhere between Cape Gris-Nez and the Varne the 
Kimmeridge clay wholly disappears, whilst somewhere to the 
west of the Varne and nearer to the English coast the Port- 
land beds also disappear and are overlaid by the Wealden 
series. Probably the Hastings beds immediately overlie 
these, and above them again is the Weald clay ; but where 
the outcrop occurs, or what is the thickness of the various 
beds, is not known. M. de Gamond’s tunnel, therefore, as 
was pointed out by Mr. William Topley in an article on the 
** Geology of the Straits of Dover,” which appeared in this 
Journal in April, 1872, would pass through a number of dif- 
ferent beds; but how many is uncertain, for it crosses the 
lines along which the changes above indicated must some- 
where occur. There is no doubt that it would pass through 
all the English divisions of the Lower Greensand, for it 
would intersect these very near the coast ; and it cannot be 
supposed that the change which these must undergo takes 
place suddenly. Farther out in the Channel it would prob- 
ably go through Weald clay, possibly it might touch the 
Hastings beds; beyond this again it might intersect the 
Portland, and finally it would cut through the Kimmeridge. 
The various beds that would be intersected by this tunnel 
are of very different characters; some are highly porous and 
some wholly impervious. 
The tunnel which it is proposed to take from St. Marga- 
ret’s Bay to near Sangatte will, it is supposed, go entirely 
through the chalk without flints. The following particulars 
of this project are taken from a paper on the ‘‘ Channel 
Tunnel ” read before the Society of Arts on the 18th March, 
1874, by Mr. W. Hawes, F.G.S., and from a ‘“‘ Statement by 
the Committee of the Channel Tunnel Company (Limited)”’ 
published in 1874. 
In 1865 Sir John Hawkshaw began his practical researches 
