THE ICE. 259 



sued by the berg must depend mainly on the direction of 

 the prevailing oceanic currents. Under favourable cir- 

 cumstances this phenomenon might be utilised to observe 

 the deep-sea currents ; for, since an iceberg, like every 

 other floating body, must direct its line of gravity parallel 

 to the impelling current, the longitudinal axis of the berg 

 must indicate the constant currents prevailing beneath the 

 changing currents on the surface. 



The oceanic currents of the Antarctic regions, on 

 which the distribution of the icebergs mainly depends, 

 are as yet known very little— practically not at all. In 

 the neighbourhood of Graham's Land, and generally 

 between it and Cape Horn, regular and comparatively 

 rapid westward currents have been observed ; they are 

 due to the regular west winds, and to their extensive 

 drifts crowded into a proportionately small space and 

 forming a belt round the great southern ocean, which 

 extends up to and beyond 6o° S. In the higher latitudes 

 the currents seem naturally to follow the winds in the 

 same manner ; they are, therefore, principally pursuing 

 a north-west direction, and gradually become a western 

 drift current. 



Near their places of origin the masses of ice, some- 

 times in huge numbers — witness the voyages of Wilkes, 

 D'Urville and Ross— disperse far and wide over the 

 expanse of ocean as the parallels of latitude increase in 

 size, till at last they disappear in the warmer waters 

 between the latitudes of 50° and 40° S. In the regions 

 visited by trading vessels a certain periodicity has been 

 observed in the frequency of icebergs. Barring excep- 

 tions, pre-eminently the giants seen in the years 1891 to 

 1896, the months of April to July inclusive, are poor- 

 est in icebergs. In August their numbers begin to 

 increase, considerably so in September and October, till 

 the maximum is reached in November and December. 

 In January the numbers diminish, still more in February, 



