148 AMTTND HELLAND ON THE FJOKDS, LAKES, 



rises and falls with the tide : this ice enables one to reach the 

 glacier and the side of the main fjord. The surface of the glacier 

 is greatly crevassed, some of the ice-peaks being full fifty feet high ; 

 still the glacier can be traversed up to a distance of about, a hundred 

 paces from the side of the fjord : here, however, it is broken up into 

 steep inaccessible crags by gaping crevasses fathoms broad, which 

 run in all directions. To this glacier there is no continuous lateral 

 moraine, but erratic blocks and dirty ice occur on its surface near 

 the margin. As a rule, no boulders were seen in the middle part of 

 the glacier. 



The breadth of the fjord varies ; in one place which was measured 

 it was about 4500 metres. The length of the glacier from the place 

 where it merges into the Inland Ice is approximately 21 kilometres, 

 A point where the side of the fjord disappears under the Inland Ice 

 is more than 150 metres above the sea ; hence the slope of the 

 glacier is not quite half a degree. The glacier passes evenly into 

 the Inland Ice, which slopes slowly upwards beyond it. 



The icebergs in front of the end of the glacier not seldom overtop 

 it by as much as 30 metres, for its terminal ice-wall rises scarcely 

 more than 40 metres from the sea. The line where the glacier ends 

 and the bergs begin is in this case easily observed, for though its 

 surface is much fissured, the outline of the bergs is even more con- 

 fused ; but the end of the glacier is indicated still more clearly by a 

 thin layer of fine dust, which distinguishes it from the cleaner sur- 

 face of the recently broken-ofF and overturned bergs. The sides of 

 the Jakobshavn Fjord are not very steep or high, and so it is not 

 difficult to traverse its south side. 



The usual method of measuring the rate of motion of a glacier, 

 by fixing a line of poles across it, cannot be applied in the ice-fjords, 

 by reason of the inaccessibility of the glacier ; it therefore has to 

 be determined by the measurement of angles from a fixed base, the 

 sharp peaks affording good points for observation. My measure- 

 ments were made with a good theodolite, and the results are given 

 in the following Table (p. 149). 



The rate of motion, where the glacier borders upon the moun- 

 tain-side, was measured by fixing sharp stones into the side of the 

 glacier, and by laying on the rock close to the glacier similar sharp 

 stones, so that the sharp points of the stones in the glacier were lying 

 quite near the points of the stones on the rock. It was observed 

 that the rate of motion close to the border of the glacier was not 

 over 0*02 metre per day. 



These numbers show that the Jakobshavn glacier flows with a 

 velocity greater than any that has hitherto been observed *. This is 

 the more surprising as its slope is only half a degree. The measure- 

 ments were made daring the daytime in summer, when the tempe- 

 rature rose at noon to 10° C. ; perhaps the motion is slower on 

 colder days. There must, however, be considerable motion during 



* [The maximum daily motion as observed by Professor Tyndall on the Mer 

 de Glace (Chamouni) was 33| inches (0-85 metre). This was in the month of 

 June. See ' Glaciers of the Alps,' p. 280.— Ed.] 





