THE FERRAR GLACIER 91 



varied and so different on different occasions, that the only way to describe them 

 fully and adequately seems to be to treat the subject more or less in narrative form. 



The first result noted was the formation of hollows partially filled with thaw- 

 water round the boulders of the moraine, a process which finally has caused the 

 disajjpearauce from sight of whole moraines. 



On December 18th, 1908, opposite the upper Cathedral Rocks, we sledged for some 

 time up a fairly steep rise of clear ice, which was seamed with small stream channels 

 up to 2 feet in diameter, and running mostly along partly recemented crevasses and 

 cracks. Many of the bottoms of the channels were covered with fine detritus, and 

 in places the channels widened into round ponds, some of which contained water. 

 The channels ran very irregularly, but seldom ran transversely across the glacier 

 for any great distance at a time, their general trend being up and down. 



The 20th was fairly calm with flaky snow, and by the morning of the 21st there 

 was 2 inches of snow on the ground, and when the sun began to play on the walls 

 of the valley, the thaw set in in good earnest. 'We reached the north wall of the 

 glacier at five o'clock in the afternoon of the 21st, and were pulled up short by a 

 precipice between 200 and 300 feet high. At the foot of the glacier ran a river 

 20 or 30 yards wide, and on the face of the glacier considerable thawing was taking 

 place. Every deeper crack and boulder hole was filled with water, and this water 

 could be heard streaming down the face of the glacier to the stream which was 

 roaring beneath the ice-cliff. 



The effect of the radiation from large rock masses is strikingly illustrated at the 

 Solitary Rocks. The ice is separated from the rock by a gully about 50 feet deep, 

 with a stream flowing at the bottom. Next comes the lateral moraine, which is very 

 thick, and still within the region in which the rock-heat is felt. The combined 

 influence of the rock material of the moraine and the radiation from the Solitary 

 Rocks has been to melt the surface of the glacier until the part occupied by the 

 moraine forms a depression from 3 to 6 feet below the level of the main glacier 

 surface, which commences as a convex rise so abrupt as to be almost perpen- 

 dicular. After this the ordinary billowy surface sets in, and the next stones 

 met with form a sub-medial moraine, which is not sufficiently thick to effect any 

 general lowering of the surface, although each stone is surrounded by its own hollow 

 filled witli thaw-water, and along the middle meanders a small stream filled Avith 

 morainic gravel, which has cut a channel about a foot deep through the glacier ice. 



The thaw reached its height the same day, and the notes taken on the spot 

 are as follows : — 



" An almost incredible amount of ice must be being removed as water. The 

 ground everywhere is honeycombed with large circular holes full of water, with the 

 large boulders or smaller morainic matter at the bottom. These holes vary from 

 the size of pin heads to large hollows 6 or 8 feet in diameter and a couple of feet in 

 depth. In those which have become deep enough for the water to be shaded from 



