W. S. Hudleston — E. Margin of N. Atlantic Basin. 151 



English Channel respectively. Immediately south of this occurs the 

 great plunge into the depths of the Bay of Biscay. The soundings 

 along the face of the suboceanic slope hereabouts are very irregular 

 and puzzling ; so much so that it is not easy to deduce any mean 

 angle of inclination. This iri'egularity in the soundings seems 

 more or less to prevail until the 2,000-fathom contour is reached, 

 beyond which the ocean floor becomes much flatter, the depths 

 ranging from 2,200 fathoms to 2,768 fathoms in the centre of the 

 Bay. At La Chapelle bank, which is about 125 miles W.S.W. 

 of Ushant, there is a fall from the 100-fathom contour to 1,900 

 fathoms in about 20 miles. This is rather steeper than 1 in 10, 

 or about 6°. No rock is marked in these soundings, but deposits 

 of a varying character. 



Following the course of the suboceanic slope for about 100 miles 

 south-east of La Chapelle bank, there is a third remarkable 

 deflection of the contours, similar to those indicated off the Little 

 Sole bank and La Chapelle bank. To judge from the soundings 

 there are some curious features here. The distance between the 

 100-fathom line and the 2,000-fathom line is only 23 miles, giving 

 a mean slope of about 1 in 11 or nearly 5°. But there are greater 

 irregularities than these. For at one spot 600 fathoms is marked 

 just outside the 100-fathom line ; whilst in another, further out to 

 sea, a distance of about seven miles, separate soundings of 880 

 fathoms and 2,100 fathoms respectively, thus giving a slope of 

 1 in 5 or 11°. In this latter case the in-egularity is not connected 

 with the edge of the 100-fathom platform, but may be said to 

 belong to abyssal depths. 



Further towards the south-east, off the town of La Eochelle, the 

 following conditions obtain. The continental platform, down to 

 the 100-fathom line, is about 130 miles wide, but the terminal edge 

 is pretty sharp, since we obtain a depth of 2,000 fathoms in the 

 next 22 miles. This gives about the same angle of inclination for 

 the suboceanic continental slope as at La Chapelle, and may 

 perhaps be taken as representing the steeper averages on the French 

 side of the Bay of Biscay, viz. 6° or thereabouts. 



The head of the Gulf of Gascony presents some remarkable 

 features which have long attracted attention, though their full 

 import is by no means certain. Here the coasts of France and 

 Spain almost form a right angle to each other, whilst the direction 

 of the suboceanic slope, flanking the Bay of Biscay, is shifted from 

 south-east to nearly due west. The contours at the head of the Bay 

 are somewhat confusing, and this is made worse hj a number of 

 incomplete soundings. The respective peculiarities of the French 

 and Spanish territories are to a certain extent prolonged under 

 water, so that the low-lying coasts of the Gironde and the Landes 

 are fully 100 miles distant from the 1,000-fathom contour, whilst 

 the more mountainous Spanish coast near Bilbao is less than 

 20 miles from it. Almost exactly in the angle, at the very head 

 of the Gulf of Gascony, the 100-fathom platform, here about 30 miles 

 in width, is pierced by the Fosse de Cap Breton, which has already 



