Page:The American Cyclopædia (1879) Volume IX.djvu/157

 ICEBERGS ICELAND 149 ern hemisphere their influence is felt in sensibly cooling the waters of the Gulf stream for 40 to 60 m. around, and on approaching them the thermometer has heen known to fall 17 or 18. When driven, as they sometimes are, in large numbers into Hudson bay, they diffuse intense cold over the northern portion of the conti- nent. The floating masses assume a variety of forms. Some spread out into sheets, which cover hundreds of square miles and rise only a few feet above the water. These are called fields, or, when their whole area can be de- fined from the mast head, floes. A number of sheets succeeding each other in one direction constitute a stream, or lying together in great collections, a pack. The surface of the sheets is often diversified by projections above the general level, which are called hummocks; they are forced up by the floes pressing against each other, and are sometimes in the form of great slabs supported by one edge. Dr. Kane noticed that these become bent by their own weight, even when the thermometer continues far below the freezing point. The most solid clear ice exhibits this yielding property of its particles. The surface of the ice fields is usually covered with snow, and when the ice is no more than 2 ft. thick it gives no trace of salt on the surface. The thicker ice contains open pools of fresh water. The bergs are real floating mountains of ice, rugged and pictu- resque, with peaks jutting high into the air, and strange forms in the glittering hard blue ice, which one easily converts into imaginary castles and grotesque architectural designs. They are occasionally seen in great numbers moving on together. Dr. Kane in his first cruise counted 280 in sight at one time, most of which exceeded 250 ft. in height, and some even exceeded 300 ft. The dimensions of the largest are measured by miles. Lieut. Parry in the first expedition of Ross encountered one in Baffin bay, 7 leagues from land, the length of which was 4,169 yards, its breadth 3,869, and its height 51 ft. It was aground in 61 fathoms. Its cliffs recalled those of the chalk on the coast of England W. of Dover. Dr. Kane saw one aground in soundings of 520 ft. which with every change of tide swung round upon its axis ; and Capt. Ross describes several he saw aground together in Baffin. bay in water 1,500 ft. deep. The officers of the French ex- ploring expedition in the Southern ocean mea- sured several bergs from 2 to 5 m. each in length, and from 100 to 225 ft. high. Capt. Dumont d'Urville reports one in the Southern ocean 13 m. long, with vertical walls 100 ft. high. The portion of these masses of ice seen above the water is only about an eighth part of their entire bulk. Such bodies, weighing hundreds of millions of tons, moved on by a broad current of water, exert a power against obstacles of which we can form little idea. In their action upon the bottom of the sea, as ex- plained in the article DILUVIUM, many geolo- gists recognize a repetition of the phenomena accompanying the distribution of the drift formation, and the production of its sands and gravel and rounded bowlders. Dr. Kane re- marks of the display of power exhibited by the movements of these huge bodies as follows:' "Nothing can be more imposing than the ro- tation of a berg. I have often watched one, rocking its earth-stained sides in steadily deep- ening curves, as if to gather energy for some desperate gymnastic feat; and then turning itself slowly over in a monster somerset, and vibrating as its head rose into the new element, like a leviathan shaking the water from its crest. It was impossible not to have sugges- tions thrust upon me of their agency in modi- fying the geological disposition of the earth's surface." Icebergs occur in great numbers in the North Atlantic in the latter part of the summer, and form the chief danger which then besets the navigation between Europe and North America. These mountains and fields of ice, however, have sometimes served as a means of safety to persons who have taken refuge on them, or floated off with them acci- dentally. Several members of Hall's exploring expedition were in 1872 rescued from a floe on which they had drifted 196 days and a distance of 2,000 miles. (See ARCTIC DISCOVERY.) ICELAND, a large island in the North Atlantic ocean, subject to the Danish crown, geograph- ically belonging to the western hemisphere, about 160 m. E. of Greenland, 600 m. W. of Norway, 500 m. N. W. of the Shetlands, and 250 m. N. W. of the Faroe islands. It is situa- ted between lat. 63 24' and 66 33' N., and Ion. 13 31' and 24 17' W.; greatest length 325 m., greatest breadth 200 m. ; < area, including ad- jacent islands, 39,758 sq. m., of which 16,243 are habitable. The population of Iceland in its most flourishing period exceeded 100,000; re- cent censuses give it as follows: 1864, 68,084; 1869, 69,506 ; 1870, 69,763. Reykiavik, the capital, has a population of about 1,400. In shape Iceland somewhat resembles a heart with its apex to the south. The coast line on the south is but little broken, several of its open- ings having been filled up during eruptions of the neighboring volcanoes ; but in all other di- rections it is deeply indented with bays, fiords, and jutting promontories. The fiords extend far inland between lofty mountains, whose sides are carved into gigantic terraces. The principal of these is Isafiord in the N. W. pen- insula. The western fiords are studded with rocky islets, and open, like those of the north and northeast, to enormous ice drifts. The chief islands on the coast are the Vestmanna isles in the south, which form a county by themselves. The best harbors are those of Reykiavik, in a bight of Faxafiord, in the southwest, Hafnarfiord in the west, Akureyri on the Eyjafiord in the north, and Vopna- fiord in the east. Iceland is apparently of vol- canic origin ; its surface in the interior is com- posed of an elevated band of palagonite tufa pierced by trachyte, and having basalt on either