8 



POLAR REGIONS. 



Polar cube made use of in these experiments, though only 

 Regions. i# B m ch in diameter, must have been campressed 

 1 with a force exceeding 19 tons ! * The whale is fre- 

 quently known to descend in these seas to the depth of 

 800 fathoms, or upwards* at which depth, (the animal 

 exposing about 154-0 square feet of surface, where the 

 weight of water is about 137 tons per square foot,) it 

 must be exposed to a pressure of more than two hun- 

 dred thousand tons, a pressure which, we are in- 

 formed, exceeds the weight of sixty of the largest 

 ships of the British navy, when manned, provisioned, 

 and fitted for a six months cruize ! t 



By the influence of currents, the waters of the Arc- 

 tic seas are mixed with those of the Atlantic, and pro- 

 bably circulated through the greater part of the ocean. 

 The prevailing current in the Greenland sea is towards 

 the south-west, with a velocity of five to twenty miles 

 per day. t In Baffin's Bay it generally sets to the 

 southward. Along the northern face of the European 

 and Asiatic continent, it is chiefly to the westward. 

 And in the Icy Sea, about Behring's Strait, it is to- 

 wards the north-east, with a velocity, as observed by 

 Lieutenant Kotzebue, of near two miles and a half an 

 hour. 



But many of these currents are superficial. While 

 the upper waters of the Greenland sea are setting con- 

 stantly to the south-westward, an under stratum is 

 probably setting the contrary way.. On what other 

 supposition are we to account for the warmth of the 

 lower water near Spitzbergen, where the mean temper- 

 ature is so far below the freezing point? It is, there- 

 fore, highly probable, that a branch of the Gulf Stream, 

 which is known to set towards the Orkney Islands, 

 may extend its course to the coast of Norway, and be 

 from thence deflected towards the north, until it is at 

 length overrun by a stratum of water, that, though 

 colder, may be specifically lighter. 



Such a transfer of the cold waters of the Arctic zone 

 and the warm waters of the south, is one of those beau- 

 tiful instances of beneficence, which the economy of the 

 globe in so many particulars presents. By this trans- 

 fer, the polar seas are preserved above the freezing 

 temperature, which prevents the whole mass of water 

 from becoming a solid bed of ice ; while on the other 

 hand the excessive heat which the sea within the tro- 

 pics would otherwise attain is greatly reduced and mo- 

 derated. We see, therefore, why the Greenland sea, 

 in the meridian where this warm submarine current 

 ascends, is navigable to a greater extent towards the 

 pole than any other part of the globe ; we also see why 

 the superficial Gulf Stream brings light floating bodies 

 across the Atlantic to the British shores, while at the 

 same time the deep current out of the Greenland sea at 

 Baffin's Bay, carries icebergs and other heavy bodies to 

 the southward along the American coast; and we also 

 have an explanation of the coldness which prevails at 

 great depths in tropical seas, and the warmth at like 

 depths in the Greenland sea. We likewise see why 

 the food of the whale, consisting of animals having lit- 

 tle locomotive powers is not dispersed into southern 

 seas, these little creatures probably possessing sufficient 

 instinct to sink to a considerable depth in the sea when 

 they are carried beyond their natural place of habita- 

 tion, by which they must [be returned to their former 

 station by the reverse action of the lower, current 



* Account oftlif Arctic Regions, vol. i.p. 203. 

 Barrow's Voyages into the Arctic Regions, p, 835. 



SECT. IV lee. 



Polar 

 Regions- 



Beyond the ?2ddegree of south latitudeandtheSSd de- 

 gree of north latitude, we have no satisfactory account of 

 any navigator having ever penetrated. The obstruction, 

 hitherto met with has not been land but ice. The extent 

 of impenetrable ice is not similar in both hemispheres, 

 nor does the margin of the polar ice describe any pa- 

 rallel of latitude, or even any regular curve. The high- 

 est attainable latitude is on the west coast of Spitzber- 

 gen, where the whale fishers annually reach the 80th or 

 8 1st degree. The next highest latitude open to naviga. 

 tors is in Baffin's Bay, where, almost every summer, 

 the ?6th or 77th parallel is accessible. On the coast of 

 Nova Zembla, and near Cape Ceverovostichnoi, a simi- 

 lar height, it appears may be attained. In all other si- 

 tuations yet known, little advance can be made beyond 

 the latitude of 72 or 7S. From careful inspection of 

 the line of impermeable ice, it would appear a space 

 containing near a million of square miles about the 

 northern pole, and a million and a half or more around 

 the southern pole, is totally unknown, being rendered 

 inaccessible to navigators by an hitherto insurmounted 

 barrier of ice. Some description of this ice will now 

 be given. 



Several different kinds of ice occur, distinguished by 

 their thickness, elevation, extent, &c. Some of these 

 it may be useful to define. 



An iceberg, or ice mountain, is a large insulated peak 

 of floating ice ; or a glacier, occupying a ravine or val- 

 ley in an arctic country. 



AJield is a sheet of ice so extensive, that its limits 

 cannot be discerned from a ship's mast-head. 



AJloe is similar to a field, but smaller, inasmuch as 

 its extent can be seen. This term, however, is seldom 

 applied to pieces of ice of less diameter than half a mile 

 or a mile. 



Drift ice consists of pieces less than floes, of various 

 shapes and magnitudes. 



Bay ice is that which is newly formed on the sea. 



A hummock is a protuberance raised upon any plane 

 of ice above the common level. 



A caff is a submarine hummock. 



A pack is a compact body of drift ice, of such a mag- 

 nitude that its extent is not discernible. 



A patch is a collection of drift ice or bay ice, of a cir- 

 cular or polygonal form. In point of magnitude, a 

 pack corresponds with a field, and a patch with a floe. 



A stream is an oblong collection of drift ice, the pieces 

 of which are continuous. 



On the freezing of sea-water the greatest part of the 

 salt it contains is deposited, and the frozen mass, how. 

 ever spongy, contains little or no salt but what is na- 

 tural to the water filling its pores. The ice at first 

 formed on the sea is generally very porous ; but, as it 

 increases in thickness, it attains considerable solidity, 

 and on being washed in fresh water, and allowed to 

 drain, is found to be quite free from salt. 



Bay ice, fields, and floes, are formed upon the sea. 

 The production of bay ice, which may take place in a 

 few hours, is often observed; and its increase, until it 

 attained the thickness of seven feet, || has been witness- 

 ed. But the formation of fieldsj which requires per- 

 haps many years, and takes place in situations not ac- 



f- Arctic Regions, ii. 250. 

 I) Parry's Voyage. 



* Ibid. i. 4. 



