r 



J. B. Dakyns — Some Snoiodon Tarns. 69 



stream from the Gribbin on one side to the cliffy ground, on the 

 other, along which the road from the mines runs. From this 

 point in the stream one can ascend to the summit of Snowdon, 

 either by the Gribbin on the south or by way of Crib y Ddysgl 

 on the north, without treading on anything but solid rock. This 

 point is, as measured by an aneroid, 40 feet below the level of 

 the lake. Consequently, unless Glaslyn is less than 40 feet deep, 

 it must lie in a rock basin, even if we neglect the fact that rock is 

 seen in the stream at only a few feet below the level of the lake. 

 We do not know the depth of Glaslyn, but it is probably more than 

 40 feet deep ; for on the north side, near the mine, rock comes 

 down to the water at a slope of 30°, and on the opposite side the 

 average slope of the rocks coming down to the lake is even more 

 than 30°. 



I conclude, then, that Glaslyn occupies a rock basin. In their 

 paper on the Lakes of Snowdon, Messrs. Marr and Adie write in 

 reference to the outflow of Glaslyn, with all the emphasis of 

 italics, " the bottom of the drift-filled depression is at a lower level 

 than the present stream, which runs at the side of the valley, being 

 separated from the lowest part by a low shelf of rock." What they 

 call the present stream is an artificial watercourse made by the 

 old miners to carry the surplus water of the lake clear of their 

 works. Comment is needless. 



Llyn Llydaw is dammed up by glacial deposits ; but at 250 yards 

 from the outlet solid rock is seen in the issuing stream and on both 

 sides of it. This point in the stream is by my aneroid from 25 to 

 30 feet below the level of the lake. Mr. Watts, however, considers 

 the first live rock seen by him in the stream to be 40 or 50 feet 

 below the level of the lake. At 250 yards from the present outlet, 

 in a N.N.W. direction, there is a depression by which the lake may 

 possibly have once discharged itself; and at about 225 yards from 

 the lake solid rock is seen in the bottom of this depression and on 

 both sides thereof. According to the aneroid this point is 40 feet 

 below the level of the lake. The space between the present 

 outflowing stream and the above-mentioned channel is occupied by 

 drift which thins away eastward, so that immediately south of the 

 little pool, shown on the Ordnance six-inch map, rock forms the 

 surface of the ground. The place where the rock is seen in the 

 said depression, as stated above, is just where it is joined by another 

 depression, which runs down from the little pool, and it is along this 

 line that Mr. Marr imagines the lake to have formerly drained. 



Consequently, in all possible outlets, real or imaginary, to Llydaw, 

 solid rock is first met with in descending from the lake, at a level 

 no lower than 40 or 50 feet below its surface. Llydaw must 

 then lie in a rock basin unless it is less than 50 feet deep ; but 

 we have reason for believing that it is much deeper than 50 feet. 

 Many years ago a man's clothes and boots were found lying beside 

 the lake. It was supposed that the owner had been drowned. A pro- 

 fessional diver was fetched up from Caernarvon, and search was 

 made for the missing body. The late Henry Owen, the well-known 



