409 
1904-5.] Study of the Lakes of Scotland and Denmark. 
compare in Denmark ; and the regular, but slow and comparatively 
slight, rise in the level of our lakes in spring, and the fall in 
summer, have, generally speaking, as far as my information goes, 
no, or only a slight, counterpart in Scotland. 
I consider the steep and precipitous shores of the Scottish lakes 
to be one of their most prominent characters (see figs. 3 and 4). 
From what I know (unfortunately only from the literature) of the 
alpine lakes of Switzerland, the Scottish lakes generally surpass 
them in this respect ; in Scotland the mountains often descend 
almost vertically into the lakes, and depths of 500 feet may he 
found only a few yards from shore. Consequently there may he 
no beach, or only a very narrow one, and I suppose the same 
may he said of the “ beine.” 
The Scottish lakes resemble the Danish ones in that the 
greatest depth is generally found near the centre of the lake, and 
that banks and well-marked deep holes are rare. Owing to the 
large amount of detritus carried down by the rivers, banks are 
common opposite the mouths of the rivers, and well-defined delta 
formations seem to be a frequent feature. Where beaches occur, 
they very often consist of pebbles and cobblestones, which during 
storms are agitated by the waves ; the erosion of the waves upon 
the rocks is often very conspicuous. 
With reference to the temperature of the water, the excellent 
observations of the Lake Survey show great differences between 
the Scottish and Danish lakes. The larger Highland lakes are 
never ice-bound, the surface temperature in winter being generally 
from 5° to 7° C. (41° to 45° F.). On the other hand, the maximum 
temperature in the same lakes in summer will never (I am 
informed) exceed 18° C. (64° F.). It will thus be seen that, 
while the surface temperature of the Danish lakes varies from a 
little below zero to 23° or 25° C. (73° or 77° F.), the amplitude of 
the variation in the surface temperature of the larger Highland lakes 
is only from about 5° - 7° C. (41° -45° F.) to 18° C. (64° F.). 
The transparency of the water in the Scottish lakes is, strange 
to say, not much greater than in the Danish lakes. Forel’s disc in 
Loch Ness disappears at 24 or 25 feet, and I am told that in other 
Scottish lakes the transparency is even less. This fact is very 
remarkable, and, so far as I know, at variance with what one might 
