The Dee. 525 



for publication in such a book as this, but the leading 

 features of the story are, that before entering the plains 

 of Cheshire, the river, passing through Bala Lake, runs 

 through the beautiful Vale of Llangollen, which as far 

 as the behaviour of the river is concerned, may on a 

 small scale be compared to that of the Moselle (see p. 534, 

 Chap. XXXI.). At the mouth of its valley the river 

 passes through a bold escarpment of Carboniferous 

 Limestone and Millstone Grit, whence suddenly bending 

 to the north it passes through flats of New Red Sand- 

 stone to its long shallow estuary beyond Chester. 



The greater part of the Silurian region on either 

 side of Bala Lake, and of the Dee, stood high above 

 the level of the sea, from remote geological times, and 

 formed a wide tableland, extending far to the south, and 

 also to the east and north-east, and on its edges rose 

 the more mountainous land, formed by the Lower 

 Silurian volcanic rocks, splendid relics of which still 

 remain in the peaks of Cadir Idris, the Arans, and 

 Arenigs. 



When, by the drainage of this old land, the Dee, 

 induced by minor undulations of the ground, began to 

 flow in its earliest channel, it is clear that its present 

 source, Bala Lake, had no existence ; for whereas the 

 river at that time must have flowed on a surface of land 

 not less high than that on either side of the present 

 valley near Corwen and Llangollen (now, in places, 

 from 1,600 to 1,800 feet high), the surface of Bala Lake 

 is only 600 feet above the level of the sea, while the 

 neighbouring watershed between the lake and Dolgelli 

 is only 200 feet higher. As the river could not flow 

 up hill, it is clear that in that early stage of its history, 

 the valley of the Dee about Bala, must have been at 

 least from 1,300 to 1,400 feet higher than it is now, and 



