114 THE ICE AGE IN CANADA. 



in outline or rise into towers and pinnacles. Most of 

 them are of a pure dead white, like loaf sugar, shaded 

 with pale bluish green in the great rents and recent 

 fractures. A few of them seem as if they had grounded 

 and then overturned, presenting a flat and scored surface 

 covered with sand and earthy matter. 



Viewed as geological agents, the icebergs are, in the first 

 place, parts of the cosmical arrangements for equalizing 

 temperature, and for dispersing the great accumulations 

 of ice in the arctic regions, which might otherwise 

 unsettle the climatic and even the static equilibrium of 

 our globe, as they are believed by some imaginative 

 physicists and geologists to have done in the so-called 

 glacial period. If the ice-islands in the Atlantic, like 

 lumps of ice in a pitcher of water, chill our climate in 

 spring, they are at the same time agents in preventing a 

 still more serious secular chilling which might result 

 from the growth without limit of the arctic snow and ice. 

 They are also constantly employed in wearing down the 

 arctic land, and aided by the great northern current from 

 Davis's straits, in scattering its debris of stones, boulders 

 and sand over the banks along the American coast. 

 Incidentally to this work, they smooth and level the 

 higher parts of the sea bottom, and mark it with furrows 

 and striae indicative of the direction of their own motion. 

 In this manner multitudes of boulders from Bafflji's bay 

 are annually distributed along the bed of the arctic 

 current off the American coast, and are buried in the 

 accumulations of mud which are being laid down on the 

 banks by this current; while in the strait of Belle-Isle 

 the same effects are being produced, on a small scale, 

 which, in the Pleistocene period, were produced in the 

 greater and wider strait then formed by the St. Lawrence 



