THE OPEN SEA IN THE ARCTIC OCEAN. 175 



Tliese salts are supplied by the under current ; for as much salt 

 as one current brings in, other currents must take out, else the 

 polar basin would become a basin of salt ; and where the under 

 current transfers its waters to the surface, there is, it is supposed, 

 a basin in which the waters, as they rise to the surface, are at 30°, 

 or whatever be the temperature of the under current, which we 

 know must be above the freezing point, for the current is of water 

 in a fluid, not in a solid state. 



480. An arrangement in nature, by which a basin of consider- 

 able area in the frozen ocean could be supplied by water coming 

 in at the bottom and rising up at the top, with a temperature not 

 below 30°, or even 28° — the freezing point of sea water — would 

 go far to mitigate the climate in the regions round about. 



481. And that there is a warmer climate somewhere in that in- 

 hospitable sea, the observations of many of the explorers who have 

 visited it indicate. Its existence may be inferred also from the 

 well-known fact that the birds and animals are found at certain 

 seasons migrating to the north, evidently in search of milder cli- 

 mates. The instincts of these dumb creatures are unerring:, and 

 we can imagine no mitigation of the climate in that direction, un- 

 less it arise from the proximity or the presence there of a large 

 body of open water. It is another furnace (§ 62) in the beautifiil 

 economy of Nature for tempering climates there. 



482. Eelying upon a process of reasoning like this, and the de- 

 ductions flowing therefrom. Lieutenant De Haven, when he went 

 in command of the American expedition in search of Sir John 

 Franklin and his companions, was told, in his letter of instruc- 

 tions, to look, when he should get well up into Wellington Chan- 

 nel, for an open sea to the northward and westward. He looked, 

 and saw in that direction a "water sky." Captain Penny after- 

 ward went there, found open wa^er, and sailed upon it. 



483. The open sea in the Arctic Ocean is probably not always 

 in the same place, as the Gulf Stream (§ 56) is not always in one 

 place. It probably is always where the waters of the under cur- 

 rent are brought to the surface ; and this, we may imagine, would 

 depend upon the freedom of ingress for the under current. Its 

 course may, perhaps, be modified more or less by the ice on the 

 surface, by changes, from whatever cause, in the course or velocity 



