CXVl 



PHILOSOPHICAL OBSERVATIONS. 



frozen ; after which, the frost penetrated more or less according to the force of the wind. 

 Tlie general effects of the cold on the snow as it fell, was to pulverize it, so that when 

 a strong breeze came it rose and filled the air like dust, to a considerable height. On the 

 other hand, the valleys, and every place into which the wind had forced the snow, became 

 so hard as to bear being formed into blocks, like Ashlar work, of large dimensions, and rolled 

 into the sledges without damage, and thus we were enabled to build the walls of our huts 

 with considerable rapicUty, our first care on halting being to find a place where the snow 

 was hard. 



ITS EFFECTS ON MERCURY. 

 The effect of cold on mercury depended materially on its purity, and I observed that the 

 longer or the oftener it was used, it froze the sooner. It was at first imagined that the lead 

 of tlie trough which is generally used in artificial horizons, amalgamated with the mercury, 

 but I always used a wooden trough, and a glass bottle to keep it in ; notwithstanchng 

 which the scum, which was always greatest in cold weather, was equally large, and every 

 year the mercury which had been used, froze at a higher temperature, until it reached 

 to thirty-one degrees, being eight degrees higher than the usual point ; while mercury, 

 which had not been exposed, retained its purity. We went through the usual experiments 

 of freezing it in a pistol-bullet mould, and firing the ball through an inch board ; as also 

 the finest almond oil, which froze at fifteen degrees, and became very hard at thirty 

 degrees, so as to penetrate, when formed into a bullet, through an inch plank at the 

 distance of five yards. 



The effect of cold on various metals was found to be the same as has been often 

 published ; but perhaps the loss of magnetic power, in no less than twelve needles of 

 compass cards, which were found on Fury beach, may be most properly attributed to 

 cold, as they were found with the needle pointing north, south, east, and west, and all 

 alike deprived of their magnetic property. The effects of cold on the icebergs was the 

 most striking ; as soon after the thermometer had sunk below zero, icebergs were heard 

 renting and tumbling to pieces with tremendous noise ; and in the spring, these immense 

 masses were seen, like as many mountains after the devastation of an earthquake. It has 

 been supposed that the cold also had the effect of giving the green and blue colour to the 

 ice ; but, although these colours were deeper and more general after than before winter, 

 still I do not think the fact to be sufl^ciently proved, that the cold is the only cause. 



