Ch. XVI.] 



ICE-DRIFTED EOCKS OF THE BALTIC 



385 







Newfoundland 



the American continent, which he conceives may have tra- 



om Baffin 



which may be compared in our hemisphere to the drifting of 



France, and England. 



Germany 



manner 



been originally detached ? We may answer that some have 

 fallen from precipitous cliffs, others have been lifted up from 

 the bottom of the sea, adhering by their tops to the ice, while 

 others have been brought down bv rivers nnrl o-la.pWs 



North America 



most of them have acquired a spheroidal form, either by fric- 

 tion or decomposition. The granite of Canada, as before re- 

 marked (p. 365), has a tendency to exfoliation, and scales off 

 in concentric coats when exposed to the spray of the sea 

 during severe frosts. The rai 



ge of the thermometer 



country usually exceeds, in the course of the year, 100°, and 

 sometimes 120° F. ; and, to prevent the granite used in the 

 buildings of Quebec from peeling off in winter, it is necessary 

 to oil and paint the squared stones. 



In parts of the Baltic, such as the Gulf of Bothnia, where 

 the quantity of salt in the water amounts in general to one 

 fourth only of that in the ocean, the entire surface freezes 

 over in winter to the depth of 5 or 6 feet. Stones are thus 

 frozen in, and afterwards lifted up about 3 feet perpendicularly 

 on the melting of the snow in summer, and then carried by 

 floating ice-islands to great distances. Professor Von Baer 

 states, in a communication on this subject to the Academy of 

 St. Petersburg, that a block of granite, weighing a million of 

 pounds, was carried by ice during the winter of 1837-8 from 

 Finland to the island of Hockland, and two other hu o 

 were transported about the years 1806 and 1814 by packed 

 ice on the south coast of Finland, according to the testimony 

 of the pilots and inhabitants, one block having travelled about 

 a quarter of a mile, and lying about 18 feet above the level of 

 the sea.* 



More recently Dr. Forchhammer has shown that in the 



VOL. I. 



* Jam. Ed. New Phil. Journ. No. xlviii. p. 439 



C C 



