NORTHERN PASSAGE TO INDIA. 5 



however, by one-half, than the rate observed by 

 Captain Cook*. 



2. By the action of the south-westerly current, a 

 vast quantity of ice is annually brought from the 

 north and east, and conducted along the east shore 

 of Old Greenland, as far as Cape Farewell, where 

 such masses as still remain undissolved, are soon 

 destroyed by the influence of the solar heat, and the 

 force of the sea, to which they then become expos- 

 ed from almost every quarter. This ice being en- 

 tirely free from salt, and very compact, appears ori- 

 ginally to have consisted of field ice, a kind which 

 perhaps requires the action of frost for many years 

 to bring it to the thickness which it assumes. The 

 quantity of heavy ice, in surface, which is thus annu- 

 ally dissolved, may, at a rougli calculation, be stated 

 at about 20,000 square leagues, while the quantity 

 annually generated in the regions accessible to the 

 whalefishers, is probably not more than one-fourth 

 of that area. As such, the ice, which is so inex- 

 haustible, must require an immense surface of sea 

 for its generation, perhaps the whole or greater 

 part of the so-called " polar basin," the supply re- 

 quired for replacing what is dissolved in Behring's 

 Strait, where the current sets towards the north, 

 being probably of small moment. The current, in 

 opposite parts of the northern hemisphere, being 



* Barrow's Voyages into the Arctic Regions, p. 358. 



