430 PROF. J. LOGAN LOBLEY, F.G.S., F.R.G.S., ON 
extraordinary circumstances. This valley, shown by the contours, 
must have been cut whiie the land was above the sea; but it 
would be very interesting to work out this point. One cannot 
bear too strongly in mind the enormous power that speed in water 
has. Take the Thames Valley, where the water runs fast it cuts 
its way. The same volume and amount of water deposits the very 
mud it has cut from the upper level on the lower level, so that it 
is not quantity only but velocity. Therefore, if we once have a 
deep gulf cut and a quantity of water behind, we have a condition 
that constitutes an erosive action and nothing would determine it 
more than the Pyrenees. There you have one of the ranges of 
mountains that stops the entire moisture or current of air on the 
north side of those mountains. One knows how complete and 
intense is the dryness in the north of the Alps, with such excessive 
damp on the south, and that condition, with the warm Atlantic 
breezes cut off by the Pyrenees, would cause a constant and strong 
stream of water down the Adour just where it wanted to cut this 
deep gulf. Under those circumstances I must say I think about 
as strong a case is made out for that origin of these gulfs as it 
would be possible to have. 
Professor Locan Lozney (in answer to a question by Mr. 
Baber) said; The configuration of the coast-line, at the time of 
the elevation, did not at all correspond with the present. It 
would more nearly correspond with the margin of the platform 
represented by the 200 fathom contour of the present day. So 
that you may take it that the coast-line at that time would be a 
long way distant from the present coast. These various indenta- 
tions would be formed by subsequent erosive action occasioned by 
local circumstances, causing a greater amount of cutting back on 
one part of the coast than the other; but the general increase of 
denuding or erosive action, would be on the southern part of 
that coast-line, and the general effect of that would be to produce 
an embayment which would be afterwards continued by the action 
of the rivers. 
The CHairmaAn.—With reference to the action of water that 
Mr. Howard referred to, one can hardly realize, unless one sees it, 
the effect of configuration on mountains when brought into contact 
with the warm atmosphere of the tropical regions. I have seen, 
four feet high, close on the ground, a cloud rise in the horizon 
not much larger apparently than a man’s hand. In half an hour, 
