88 FORESTRY OF NORWAY. 
dals fjeld and the Hallingsdal fjeld, with a length of 186 
kilometres, and a basin of '5230 square kilometres. In 
itself the Dramselv has a length of 263 kilometres, and a 
basin of 16,890 square kilometres, 
’ The rivers of Finmark, the Altenelv and Tanaely—the 
latter-of which is, after the Glommen and the Dramselv, 
the third greatest river in Norway—do not themselves 
expand into lakes, but they receive affluents from a great 
many small lakes, and they pass through some others. 
‘The river Patsjoka is the flow to Varanger fiord of the 
‘great’ lake Enare, measuring 2530 square kilometres, 
situated in Finnish Lapland at an altitude of 250 metres. 
In my account of my visit to Christiansand mention is 
made of the Toppdal river, and: the Torristal, or Otterdale 
river, 
Of the Topdalselv, debouching’ to the east of Chris- 
tiansand, it is stated that it is the discharge of the eastern 
part of the mountains of Sstersdal, and has a length of 
136 kilometres, with a basin of 1,900 square kilometres. 
Of the Otterelv, the river I visited, and which debouches 
into the western part of Christiansand, he states that it 
flows from the midst of the mountains of the Ssetersdal, 
receiving affluents from the Byklefjeld, the most southern 
part of the Langfjeld, and that it has a length of 226 
kilometres, with a basin of 3,660 square kilometres. 
Of the waterfalls in Norway mention has been made 
again and again in preceding chapters. Of such the most 
remarkable, on account of the quantity of water, and at 
the same time, the most important, in consequence of its 
proximity to the sea, is the Sarpfoss, formed by the Glom- 
men near its embouchure. The flow of this mass of water 
varies from 100 to 150 cubic metres per second in winter, 
and from 2000 to 3000 cubic metres per second when the 
river is in flood ; and some years it has amounted to 4000 
cubic metres, The mean flow may be estimated at 800 
cubic metres per second. The perpendicular height of 
the fall of Sarpfoss is 21 metres, 
