PliiUp LaJ;c — Bala Lake and River System. 



205 



I system of North Wales. Mr. Marr, however, finds no evidence of 

 the differential movements which seem in Wales to have played so 

 important a part in modifying the original drainage system. 



My thanks are also due to Mr, A. L. Hall, of Caius College, 

 Cambridge, and to Mr. J. B. Scrivenor, of Hertford College, 

 Oxford, for invaluable assistance in sounding Bala Lake; and I am, 

 besides, under obligation to Mr. Hall for help in other portions of 

 the work. 



Fig. 1. 



Contours beloAV 1,000 feet iudicated by dotted lines. 

 Contours 1,000 feet and over indicated by continuous lines. 



Topography of Bala Lalce and of tlie valley in which it lies. 



Bala Lake (see Fig. 1), the largest natural sheet of water in 

 Wales, is nearly four miles long and about half a mile wide. It is 

 oblong in shape and unusually regular, the two sides being remark- 

 ably straight and parallel, so that the width is nearly uniform 

 throughout. The straightness of the sides is interrupted only by 

 the peninsulas of Llafar, Llangower, and one or two smaller points ; 

 and all of these are mere tongues of alluvium. At each end thei-e 

 is a wide alluvial plain, and the lake owes its symmetry partly, 

 but not entirely, to these alluvial deposits. 



On February 19, 1885, the surface of the water was determined 

 by the Ordnance Survey to be 5299 feet above Ordnance Datum ; ' 



» Merionethshire (6 inches to 1 mile) : Quarter-sheets xxii S.W., xxii N.W., and 

 xxii N.E. 



