1853.] SUTHERLAND — ARCTIC REGIONS. 305 



column of ice, ascending through the orifice or " fuze hole," and 

 always amounting to about one-tenth of the whole mass of water 

 used, retained its cohesive property so perfectly, that without being 

 broken, and although only half an inch in diameter, the whole appa- 

 ratus weighing four to five pounds could be raised by its means, and 

 sometimes even inverted. But at lower temperatures the ascending 

 column escaped with a slight crepitating sound, and frequently with 

 explosive reports, accompanied each by a sudden propulsion of a 

 portion of it to a distance of several feet ; it was so friable too that 

 it separated into discs of half or a quarter of an inch in thickness, 

 and sometimes crumbled to fragments between the fingers. The im- 

 portant points, relative to the plasticity of ice, contested some years 

 ago by Prof. J. Forbes and Mr. Hopkins come within this field of 

 research ; they are well known, and need not be recounted here. 



Icebergs. — From what has been observed in the Alps, it may be 

 considered a settled question that the dowilward motion of the glaciers 

 is constant and comparatively unaffected by low temperatures ap- 

 plied to the surface, especially when the depth of the solid ice 

 amounts to several hundred feet. In the Alps, and even within the 

 tropics, they travel great distances from the snow-clad heights, until 

 gradually they frequently descend into the regions habitable by man, 

 where they undergo dissolution by the increase of temperature. In 

 Greenland, after descending into the sea through the valleys, they 

 retain their hold of the land *, until the buoyant property of water 

 upon ice comes into operation, and then they give birth to icebergs, 

 sometimes of enormous dimensions f . The constant rise and fall of 

 the tide exerts great power in detaching these floating ice-islands. 

 By it, a hinge-like action is set up as soon as the edge of the glacier 

 comes within its influence, and is carried on, although the surface of 

 the sea for many leagues around is covered with one continuous 

 sheet of ice. After summer has set in and somewhat advanced, the 

 surface-ice either drifts away or dissolves, and then we have winds 

 prevailing in a direction contrary to what they had been during the 

 cold season of the year ; and the result of this is a great influx of 

 water into Davis' Straits, which causes tides unusually high for 

 other seasons of the year, and which in their turn set at liberty whole 

 fields of icebergs, then to commence their slow southward course. 

 In August 1850 the number set free in a deep fiord near Omenak, 

 North-east Bay, so occupied the navigable passage out of the harbour 

 at that settlement, that the Danish ship which had but a few weeks 

 previously entered the harbour was in great danger of being de- 

 tained for the winter. In the same month in 1852, the whole of 

 the coast southward from Melville Bay, extending over a space of 

 180 mdes in length and probably 12 to 15 miles in breadth, was 

 rendered perfectly unnavigable by any means whatever. When we 

 sailed along that portion of the coast about the middle of August in 



* Some of these glaciers of Northern Greenland push forward into the sea to 

 the extent of from one to three miles. 



t For the description of an immense iceberg, 200 feet high above the sea and 

 two miles in length, see Sutherland's Journal, vol. i. pp. 61, 62. 



