NATURAL HISTORY. 



539 



treene^ to a transport ice. They 

 are as permanent as the rocks on 

 which they rest : For although 

 large portions may be frequently 

 separated, yet the annual giowth 

 replaces the loss, and probably, 

 on the whole, produces a perpe- 

 tual increase. I have seen those 

 styled the Seven Icebergs, situated 

 in the valleys of the north-west 

 coast of Spitzbergen ; their per- 

 pendicular front may be about 

 300 feet in height ; the green 

 colour, and glistening surface of 

 which, form a pleasing variety in 

 prospect, with the magnificence 

 of the encompassing snow-clad 

 mountains, which, as they recede 

 from the eye, seem to " rise crag 

 abore crag," in endles? perspec- 

 tive. 



Large pieces may be separated 

 from those ice- bergs in the sum- 

 mer season, when they are par- 

 ticularly fragile, by their ponde- 

 rous overhanging masses over- 

 coming the force of cohesion J or 

 otherwise, by the powerful expan- 

 sion of the water, filling any ex- 

 cavation or deep-seated cavity, 

 when its dimensions are enlarged 

 by freezing, thereby exerting a 

 tremendous force, and bursting 

 the whole asunder. 



Pieces thus or otherwise de- 

 tached, are hurled into the sen 

 with a dreadful crash ; if they are 

 received into deep water, they are 

 liable to be diifted off the land, 

 and, under the form of ice-islands, 

 or ice-mountains, they likewise 

 still retain their parent name of 

 icebergs. I much question, how- 

 ever, if all the floating bergs seen 

 in the seas west of Old Greenland, 

 thus derive their origin ; their 

 number is so great, and their di- 

 mensions so immense. 



Magnitude of Icebergs. 



It aU the floating islands of ice 

 thus proceed from disruptions of 

 the icebergs generated on the 

 land, how is it that so few are 

 met with in Greenland, and those 

 comparatively so diminutive, whilst 

 Baffin's Bay affords them so plen- 

 tifully, and of such amazing size ? 

 The largest I ever saw in Green- 

 land, was about a thousand yards 

 in circumference, nearly square, 

 of a regular flat surface, twenty 

 feet above the level of the sea ; 

 and as it was composed of the 

 most dense kind of ice, it must 

 have been 1.50 or 160 feet in 

 thickness, and in weiglit about 

 two millions of tons. But masses 

 have been repeatedly seen in 

 Davis' Straits, near two miles in 

 length, and one-thijd as broad, 

 whose rugged mountainous sum- 

 mits were reared with various 

 spires to the height of more than 

 a hundred feet, whilst their base 

 must have reached to the depth 

 of a hundred and fifty yards be- 

 neath the surface of the sea. 

 Others, again, have been observed, 

 possessing an even surface, of 

 five or six square miles in area, 

 elevated thirty yards abo^c the 

 sea, and fairly run aground in 

 water of ninety or a hundred 

 fathoms in depth ; the weight of 

 wliich must have been upwards 

 of two thousand millions of tons ! 



Icebergs may arise in sheltered Bays 

 of the Land. 



Spitzbergen is possessed of every 

 character which is supposed to be 

 necessary for the formation of the 

 largest icebergs ; liigh mountains, 

 deep extensive valleys, intense 



frost. 



