498 REVIEWS — THE STORY OF A BOULDER. 



becoming top-heavy, reels over, exposing to light rocky fragments still firmly 

 imbedded. These, as the ice around them gives way, are dropped one by one 

 into the ocean, until at last the iceberg itself melts away, the mists are dispelled, 

 and sunshine once more rests upon the dimpled face of the deep.* If, however, 

 before this final dissipation, the wandering island should be stranded upon some 

 coast, desolation and gloom are spread over the country for leagues. The sun is 

 obscured, and the air is chilled ; the crops will not ripen; and to avoid the hor- 

 rors of famine, the inhabitants are fain to seek sonae more genial locality until 

 the ice shall have melted away ; and months may elapse before they can return 

 again to their villages. 



The icebei'g melts away, but not without leaving well-marked traces of its ex- 

 istence. If it disappear in mid-ocean, the mud and boulders, with which it was 

 charged, are scattered athwart the sea-bottom. Blocks of stone may thus be 

 carried across profound abysses, and deposited hundreds of miles from the parent 

 hill: and it should be noticed, that this is the only way, so far as we know, in 

 which such a thing could be effected. Great currents could sweep masses of rock 

 down into deep gulfs, but could not sweep them up again, far less repeat this pro- 

 cess for hundreds of miles. Such blocks could only be transported by being lifted 

 up at the one place and set down at the other ; and the only agent we know of, 

 capable of carrying such a freight, is the iceberg. In this way, the bed of the sea 

 in northern latitudes must be covered with a thick stratum of mud and sand 

 plentifully interspersed with boulders of all sizes, and its valleys must gradually 

 be filled up as year by year the deposit goes on. 



But this is not all. The visible portion of an iceberg is only about one-ninth 

 part of the real bulk of the whole mass, so that if one be seen 100 feet high, its 

 lowest peak may perhaps be away down 800 feet below the waves. Now it is 

 easy to see that such a moving island will often grate across the summit and along 

 the sides of sub-marine hills ; and when the lower part of the berg is roughened 

 over with earth and stones, the surface of the rock over which it passes will be 

 torn up and dispersed, or smoothed and striated, while the boulders imbedded in the 

 ice will be striated in turn. 



But some icebergs have been seen rising 300 feet over the sea ; and these, if 

 their submarine portions sank to the maximum depth, must have reached the enor- 

 mous total height of 2700 feet — that is, rather higher than the Cheviot Hills.f By 

 such a mass, any rock or mountain-top existing 2400 feet beloAV the surface of the 

 ocean would be polished and grooved, and succeeding bergs depositing mud and 

 boulders upon it, this smoothed surface might be covered up and suffer no change 

 until the ocean-bed should be slowly upheaved to the light of day. In this \va,j, 

 submarine rock surfaces at all depths, from the coast line down to 2000 or 3000 

 feet, may be scratched and polished, and eventually entombed in mud. 



* That beautiful expression of jEscliylus occurs to me, so impossible adequately to clothe 

 in English : avqpidfxov yeXafffjLa Kvjxartav. Who that has spent a calm summer day upon 

 the sea, has not realized its force and delicate beauty ? 



t In the American Journal of Science for 1843, page 155, mention is made of an iceberg 

 aground on the Great Bank of Newfoundland. The average depth of the water was about 

 500 teet, and the visible portion of the berg from 50 to 70 feet high, so that its total height 

 must have been little short of 600 feet, of which only a tenth part remained above water. 



