Philip Lake — Bala Lake and River System. 207 



Westmoreland,^ it is impossible now to maintain this view without 

 a closer examination of other possible outlets. 



Now, although Bala Lake empties itself through the Dee, which 

 flows in an easterly direction from its north-eastern end, this is not 

 what the general topography of the district would lead us to expect. 

 The lake does not lie in the continuation of the Vale of Edeyrnion 

 (as the valley of the Dee between Llandderfel andCorwen is called) ; 

 but it lies in a very distinct and well-defined valley which runs 

 from the sea at Barmouth in a north-easterly direction to the town 

 of Bala ; and this valley is entirely shut off from the Vale of 

 Edeyrnion by a ridge of hills, except for the narrow gorge through 

 which the Dee now flows. This great valley is in the line of the 

 Bala fault, and from Dolgelly to Bala its direction is S.W.-N.E,, 

 which is precisely that of the lake ; while the general direction of 

 the Dee for several miles after leaving the lake is nearly west to east. 



It is true that the actual watershed crosses the valley at Pant- 

 gwyn, and that on the one side the waters flow into Bala Lake and 

 thence to the Dee, while on the other side they flow into Afon Wnion 

 and finally into the estuary of the Mawddach. But the watershed 

 forms no feature in the valley, and the slope which determines the 

 direction of flow is so slight that it requires a very careful examina- 

 tion of the streams to discover the position of the water-parting. 

 The floor of the valley in no place rises to a greater height than 

 774 feet above the sea, i.e. about 374 feet above the bottom of the 

 lake. The depth of the valley near this point is entirely out of 

 proportion to the size of the little rivulets which now flow in it. 



Continuing the line of the valley in which Bala Lake lies, it 

 leads us in a north-easterly direction, not along the course of the 

 Dee, but into the valley which is now occupied by Nant Meloch 

 and its tributary from Cors-y-Sarnau. This is a stream which flows 

 from north-east to south-west, and which would enter the lake near 

 Bala, were it not that before it reaches that point it is suddenly 

 deflected almost at right angles, so as to join the Dee at Melin 

 Meloch. 



If the gorge near Llandderfel were blocked, this stream would 

 flow into Bala Lake, and Bala Lake would empty itself into the 

 Wnion ; and we should have a continuous flow of water down what 

 is now undoubtedly a continuous valley running from north-east to 

 south-west. 



From these topographical considerations alone, it appears probable 

 that the drainage of the district originally flowed in this direction, 

 and that the present outlet of the lake is of subsequent formation. 

 In favour of this view it may be noted that at the foot of the lake 

 there is an alluvial plain, which is even more extensive than that 

 which is now being formed at its head ; and also that the floor of the 

 lake appears to slope from north-east to south-west. 



^ See, especially, "The Tarns of Lakeland" : Qnart. Journ. Geol. Soc, vol. li 

 (1895), pp. 35-48. " Additional Notes on the Tarns of Lakeland" : ibid., vol. lii 

 (1896), pp. 12-16. "On the Lake Basins of Lakeland": Proc. Geol. Assoc, 

 •vol. xiv (1896), pp. 273-286. 



