LAKES. 
255 
colour to ultramarine and violet, the constant changes 
and patterns varying with every breath of wind, in 
short the life and glory and beauty of the lakes are 
entirely due to the light of the sun. 
The Beine or Blancfond. 
If, on a fine, still day, we look down the Lake 
of Geneva from some neighbouring height, we see 
the azure blue of the deep water fringed by a clear 
grey or greenish margin. This is the “Beine” or 
“Blancfond” where the shallowness of the water 
renders visible the grey or yellowish tint of the 
bottom. Such a shallow fringe or margin encircles 
many of the Swiss lakes, and may be explained as 
follows: The waves gradually eat away the bank, giving 
rise to a small cliff and talus (Fig. 69 p. 256). Tire 
loose stones and sand are gradually rolled down- 
wards, forming a slightly inclined terrace (Fig. 69, 
K, M) which finally ends in a steep slope. This 
terrace is known as the Beine or Blancfond. The 
depth of the Beine depends on that to which the 
water is agitated by the waves; it is less, therefore, 
in sheltered, and greater in exposed, situations. In 
the Lake of Geneva it ranges between 1 and 4 
metres. It falls into two parts, the inner (K, C) due 
to erosion, and the outer (C, M) to deposition. The 
