8 G. F. Wright—The Muir Glacier. 
when the tide and wind were favorable, the inlet would for a 
few hours be comparatively free from floating ice; at other 
times it would seem to be full. 
5. Subglacial Streams. 
The movements of the glacier in its lower. portions are prob- 
ably facilitated by the subglacial streams issuing from the front. 
There are four of these of considerable size. ‘wo emerge in 
the inlet itself, and come boiling up, one at each corner of the 
ice-front, making a perceptible current in the bay. There are 
also two emerging from under the ice where it passes the 
shoulders of the mountains forming the throat of the glacier. 
These boil up, hke fountains, two or three feet, and make their 
way through the sand and gravel of the terminal moraine for 
about a mile, and enter the inlet 250 or 300 yards south of the 
ice-front. These streams are perhaps three feet deep and from 
twenty to forty feet wide, and the current is very strong, since 
they fall from 150 to 250 feet in their course of a mile. It is ° 
the action of the subglacial streams near the corners of the 
inlet which accounts for the more rapid recession of the glacier 
front there than at the middle point projecting into the water 
south of the line joining the east-and-west corners. It was 
also noticeable that the falls of ice were much more frequent 
near these corners, and the main motion of the ice as after- 
wards measured was, not toward the middle point projecting 
into the inlet, but toward these corners where the subglacial 
streams emerged below the water. 
6. Direct measurement of the Velocity. 
No small difficulty was encountered in securing direct meas- 
urements of the motion; and, as the results may be questioned, 
I will give the data somewhat fully. As it was impossible to 
cross the main current of the glacier, we were compelled to 
take our measurement by triangulation. But even then it 
seemed at first necessary to plant flags as far out on the ice as 
it was safe to venture. This was done on the second day of 
our stay, and a base-line was established on the eastern shore, 
about a mile above the mouth, and the necessary angles were 
taken. But on returning to repeat the observations three or 
four days afterwards it was found that the ice was melting 
from the surface so fast that the stakes had fallen, and there 
were no means at command to make them secure. Besides 
they were not far enough out to be of much service. It ap- 
peared also that the base-line was on a lateral moraine, which 
was, very likely, itself in motion. But by this time it had be- 
