234 ACCOUNT OF THE ARCTIC REGIONS. 



mean specific gravity of ice being considered as 0.92» 

 it will appear, that the proportion floating above to 

 that below the surface, when plunged in fresh-water, 

 temperature 32% inust be as 1 to 11.5. But the 

 specific gravity of ice, when compared with the 

 sea-water occurring on the Spitzbergen coast, tem- 

 perature 35°, was ascertained to be 0.894 to 0.900 ; 

 as such, when ice floats in the sea, the proportion 

 above to that below the surface, appears, by calcu- 

 lation, to be as 1 to 8.2. For every solid foot of 

 ice, therefore, v/hich is seen above water in a 



measuring tlie }iart that floated above the surface in rain and 

 sea-water, at different temperatures. This method, however, 

 was found to give discordant results, on account of different 

 sources of error to which it was liable. As such, I tried the 

 specific gravity, by weighing different pieces of ice in the air, 

 when the weather was cold, and then in fresh and salt water, 

 at a freezing temperature, with a piece of metal attached to 

 each specimen, to sink it. The difference between the weight 

 of the ice in water, with the load attached, and the weight in 

 water of the load singly, showed the difference between the 

 weight of the ice, and an equal bulk of water ; consequently, 

 this difference, added to the weiglit of the ice in air, afforded 

 the v/eight of an equal bulk of water ; and the comparison of 

 the two latter weights, gave, in the usual way, the specific 

 gravity of the ice. 



These experiments were always performed in the open air, 

 when the temperature was 30° to 32". The different speci- 

 mens were dried with a coarse cloth before they were weighed 

 in air, and immediately afterwards were weighed in salt and 

 fresh water, at a freezing temperature. Tlie particulars of 

 these experiments will be found in the Appendix, No. VIII. 



