1 7 8 



NA TURh 



[June 19, 1884 



The side limit of the glacier, where it sometimes flows 

 clown the slope on its right and left, is also marked by a 

 similar line of trees, the intervening space of about 300 

 yards being partly strewn with loose stones and coarse 

 gravel, and partly perfectly bare, highly polished, striated 

 rock. This rock has a somewhat remarkable appearance, 

 as it is composed of a fine dark stone (a metamorphosed 

 slate ?) with intrusive parallel veins of white crystalline 

 rock. The bands of black and white are very even in 

 width, and there is as much of one rock as the other, so 

 that, as the strike of the veins is in the same direction as 

 the flow of the glacier, they look, at a little distance, like 

 gigantic stria?. 



I marked the foot of this glacier in December 1882, and 

 found by March 1883, after the summer, that it had re- 

 treated 30 yards. After the winter, I fully expected to 

 find that it had again advanced, but in December 1S83 

 the edge of the ice was 50 yards farther back than in 

 the previous December. They reported a very mild winter 

 at Sandy Point, but I was not prepared to find the glacier 

 retreating throughout the year, as it was manifestly at its 

 full limits not many years ago. 



I could not procure any evidence as to its rate of 

 motion. The sides are so broken up, by great pieces 



falling off and slipping down the slope, that it is almost 

 impossible to get at the main body of the ice to put a 

 mark in. 



The head of West Havergal Bay, into which the gla- 

 cier stream falls, is filled with a level bottom of sand with 

 about 10 fathoms of water over it. This has a very steep 

 edge to the deeper part of the basin. I imagine this to 

 have been the delta formed by the glacier stream, when 

 the land was at a slightly higher level. It is very rare 

 in the Straits of Magellan to have anything but uneven, 

 rocky bottoms to these deep basins, and they are gene- 

 rally steep to the edge of the shore. I have only found 

 these sandy flat bottoms in the vicinity of glaciers, and 

 as a sandy flat always forms around the embouchure 

 of the glacier streams, a subsidence of the land would 

 account for the existence of flats under water. 



The hill-sides around Havergal Bay, where bare, show 

 glaciation to a height of about 700 feet above the present 

 sea-level. I think the land must have been higher when 

 the ice was at this height, as the channel just below some 

 of these marked hills being 60 fathoms deep, it would 

 require the glacier to be 1000 feet thick, which seems to me 

 hardly possible with such a small area for the produc- 

 tion of neve as there is now, even supposing a greatly 



Havergal Bay, Strait of Magellan. End of Gl.i 



increased fall of snow and a much lower average of 

 temperature than at present. 



I visited one of the glaciers remanies on the north-west 

 side of Mount Wharton. It lies in a hollow about 1500 

 feet above the sea, and at the foot of cliffs 1000 feet high 

 or more, and is three-quarters of a mile long by 400 yards 

 wide. It is an excellent example of regelation, as the 

 fragments which form it must be dashed to small pieces 

 in their fall. It was at the end of summer, and only 

 insignificant bits were coming over the cliff from the ice- 

 field above. These fell on the glacier remaniS broken 

 into minute fragments with a patter as of heavy hail. 

 Larger masses would be similarly broken, and yet the 

 ice-mass was as clear and compact as if it had never been 

 disturbed. 



There were signs here on all sides, in the striations and 

 mouton tie shape of all the rock above it, that this re- 

 organised mass was once much larger ; and 500 feet below, 

 on a tolerably level part of the otherwise steep hill-side, 

 bordering the stream that issues from the glacier, were 

 low lines of moraine that were evidently once at the lower 

 part of its sides. 



A snow-field on a flattish mountain 3100 feet high, near 

 Mount Wharton, has no proper glacier, but the ice falls 

 over precipices and forms glaciers remanie's: 



Glacier from Mount Wyndham 



Mount Wyndham, on the opposite side of the Strait to 

 Mount Wharton, sends a glacier down a valley, but has 

 no surface moraine nor blocks. Its length is about two 

 miles and a half, and the width, at the bottom, half a mile. 

 Like others, it is very steep, and its surface is broken into 

 pinnacles with deep crevasses. As I never saw the land- 

 ward side of Mount Wyndham, I cannot exactly say what 

 other glaciers may take their rise in it, nor what the size 

 of the snow-field may be, but it probably does not exceed 

 more than four or five square miles. 



The foot of the glacier is not more than 100 feet above 

 the sea, and is half a mile from the head of Glacier Bay, 

 in a broad flat between the mountain slopes. A thick 

 belt of tangled forest intervenes. This glacier is much 

 shrunk also, a wide space of ground, covered with rounded 

 stones, sand, and gravel, extending all round the foot to 

 the edge of the trees in front, and the hills at the sides. 



Signs of glaciation are abundant about this glacier, 

 at far higher levels than it now reaches. Glacier Bay 

 itself has been filled with it. This is a deep basin (70 

 fathoms deep) with islands stretching across its entrance. 

 Rock Island, the largest of these, is moutonnie to the top, 

 560 feet, and the striae are plain to see on its smooth 



