60 
Proceedings of Royal Boeiety of Edinburgh. 
SESS. 
The ice-dam, which lies in front of the pond-lakes, is about 300 
feet high, and, to this extent, it closes up the entrance to the valley 
in which they lie, and which extends northwards amid the rocks 
for about 4 kilometres. During the autumn and winter the ice 
becomes tight, partly on account of the movement of the glacier, 
and partly because the snow and ice freeze together. In this condi- 
tion, when the spring thaw sets in, the water in the lowest pond- 
lake begins to rise and soon reaches the level of the upper, and the 
two become one lake. But still the water rises, and continues to do 
so till it finds an outlet over the surface of the glacier. A natural 
consequence of this rising of the water is, that large masses become 
detached from the glacier, because the ice adjacent to the Lure-Peak 
is greatly fissured. Icebergs from 400 to 500 feet in diameter are thus 
formed, which float about in the lower part of the lake, but only 
the smaller portions go far up, because the water there is shallower. 
“ As soon as the water reaches the top of the glacier it begins to 
clear a way for itself by excavating a channel through the ice, and 
it depends on the amount of ice the stream can melt each day how 
great its volume may be. In this way it takes three or four weeks 
to empty the valley of its contents, during which the Eembidalsfos 
is very fine, on account of the extra quantity of water in the river. 
“ This is the usual way in which the water accumulated in the 
valley of the pond-lakes finds an exit. But in certain years it forces 
a passage beneath the glacier, and, in this case, a dangerous flood 
ensues, because the force of the water is so great that nothing can 
stand in its way, and so the whole escapes in a few days. On such 
an occasion the portion of the glacier below the pond-lakes presents 
a most wonderful spectacle. The water is forced up through the 
numerous holes and fissures in the ice, and reappears on the surface 
of the glacier like so many geyser-fountains playing over it, because 
the pond-lakes, being on a much higher level, the pressure is very 
great, and the openings in the ice are small in comparison with the 
volume of water. It is thus a very uncommon sight to see the 
glacier, as it were, washing itself ; and this is the reason that the 
ice of this glacier is so much cleaner and finer than that of any 
other. The Kembidals-glacier is, therefore, in the proper sense of the 
words, a glacier which has actually washed itself. 
After the pond-lakes are emptied another strange spectacle may 
