The Muir Glacier. 9 
come evident that the masses of ice uniting to compose the 
main stream of motion retained their features so perfectly from 
day to day that there was no difficulty in recognizing many of 
them much farther out than it was possible to venture to plant 
stakes. Accordingly another base-line was established on the 
east side opposite the projecting angle of ice in the inlet. From 
this position eight recognizable points in different portions of 
the ice-field were triangulated, —the angles being taken with a 
sextant. Some of the points were triangulated on five differ- 
ent times, at intervals from the eleventh of August to the sec- 
ond of September. Others were chosen later and triangulated 
a fewer number of times. In all cases given the angles were 
taken independently by Mr. Prentiss Baldwin of Cleveland 
and myself and found to agree. 
The base-line finally chosen (marked B on fig. 2) was at 
the foot of the mountain exactly east by the compass from the 
projecting angle of ice in the inlet. The elevation of the base- 
line was 408 feet above tide,—corresponding to that of the 
ice-front. The distance of this projecting point of ice (marked 
C on fig. 2) from the base-line was 8,534 feet, and it re- 
mained very nearly stationary during the whole time,—show- 
ing that the material breaking off from the ice-front was equal 
to that pushed along by the forward movement. Satisfactory 
observations were made upon eight other points numbered and 
located on fig. 2. 
No. 1 was a pinnacle of ice 1,476 feet N. by 30° E. from C. 
The movement from Aug. 14 to Aug. 24 was 1,653 feet H. by 
5° S. After this date the pinnacle was no longer visible, hav- 
ing disappeared along the wasting line of front between OC and 
the subglacial stream at the northeast corner of the inlet. 
No. 2 was a. conspicuous pinnacle of ice 2,416 feet N. by 
16° E. of C. Observations were continued upon this from Aug. 
11 to Sept. 2. The total distance moved during that time was 
1,417 feet, or about sixty-five feet per day. From Aug. 14 to 
Aug. 24 the movement was 715 feet, or about seventy-one feet 
per day. The difference is, however, perhaps due to the neg- 
lect to record the hours of the day when the observations were 
taken. As these observations were wholly independent of 
each other, their substantial concordance demonstrates that 
there was no serious error in the observations themselves. 
The direction of movement of this point of ice was very nearly 
the same as that of the preceding, namely, E. 16°S. This 
also is towards the subglacial stream emerging from the north- 
east corner of the inlet. 
No. 3 was observed only from Aug. 20 to Aug. 24. It was 
situated 3,893 feet N. by 62° HE. of OC, and moved 105 feet in a 
westerly direction, The westerly course of this movement 
