“LAKES, 3 
metres above the level of the sea, consequently its basia, 
over a great extent, is 330 metres (1110 feet) below the 
level of the sea, which only attains to this depth in the 
‘ outer portion of the Christiania fiord. 2 
_The Storsjo, in the valley of Rendal, has a length of 35 
kilometres, and an area of 47 square kilometres. It empties 
its waters into the Glommen. Its altitude is 257 metres, 
its depth is 301 metres, its basin sinks 44 metres (147 
feet) below the level of the sea, from which, by the course 
of the Renelv and the Glommen, it is 340 kilometres 
distant. 
The Tyri fiord, with an altitude of 64 metres, has a 
depth of 281 metres, so that the bottom is 217 metres 
(723 feet) below the level of the sea. 
Many small lakes situated near the interior extremity 
of the deep fjords of the prefecture of Bergen and Roms- 
dal have a depth as great as that of the fiords to which 
they are adjacent. Thus the Horningdalsvand in the 
prefecture of Romsdal, at an altitude of 56 metres, with 
an area of 57 square kilometres, has a depth of 486 
metres, so its bottom is 429 metres, 1,430 feet below the 
level of the sea, from which it is distant only 10 kilometres. 
On the south-west coast, in the low lying level country of 
Jaderen, there are lakes ot fresh water, separated from the 
sea by only banks of sand, with which they have nearly 
the same level. The largest of them, the Orrevand, 
measures 11 square kilometres. 
It may be premature to speak of the means by which 
valleys of such depth have been dug, or ploughed out of 
the solid earth. But the subject will not be overlooked ; 
it will be discussed in the chapter entitled Mechanical 
Action of Glaciers, Here it is deemed sufficient to 
intimate that these are considered as valleys occurring in 
the thalweg or bed of a river or a rivulet, which was filled 
before the stream could continue its course beyond, and 
which are kept full by supplies equivalent to some extent 
to the current. or delivery passing on. 
