482 CURRENTS AND WHALING. 



to the anomalous periodic changes that are known to occur, placing 

 all calculations at nought. 



The trades, the monsoons, and other steady or periodic winds, as 

 well as the variable winds of the temperate zones, are either caused 

 or much influenced by the manner in which temperature is distributed 

 over the surface of the ocean, by the polar and equatorial streams. It 

 is therefore proper that, as immediately connected with this subject, 

 we should mention the spaces which lie between the zones of the trade 

 and westerly winds, and which are usually the seat of light variable 

 winds and calms. The existence of such a zone in the North Atlantic 

 has long been known, and we have assured ourselves of the existence 

 of similar zones in the other oceans, though not to so great an extent. 

 They lie on each side of the parallels of 30° in both hemispheres, and 

 are about three hundred miles in breadth. Leaving out of account the 

 effect of the great currents of the atmosphere, we find this space to 

 be a sort of eddy, in which the polar and equatorial flow of waters 

 neutralize each other, and where therefore, all the floating matter that 

 is brought by both must accumulate. I shall have occasion to refer to 

 this view of these zones hereafter, as connected with the subject of 

 whaling. 



If, however, the view I have taken of the flow of the waters of the 

 ocean and their results be correct, which the facts we observed and 

 those I have quoted from the authority of others, scarcely leave a 

 doubt of, we may see the admirable provisions of nature by which 

 the Creator has regulated the fluid mass of the ocean, in its endless 

 gyrations seeking to attain a state of equilibrium which it never 

 reaches, at the same time and by the same course distributing the 

 excess of the tropical heats throughout the whole surface of the globe, 

 and bringing towards the equator the icy masses which would other- 

 wise accumulate in the frozen zones. 



But, putting aside the partial observations that have been detailed in 

 the preceding pages, relative to the direction and extent of the great 

 streams and currents of the ocean, whether surface or submarine, the 

 habits of the spermaceti whale alone would furnish strong circum- 

 stantial evidence that such currents do exist, and that they are variable 

 in their strength, and even in direction, according to the season. 



It is well known to whalers that the favourite and appropriate food 

 of the sperm whale is a gelatinous medusa ; which, however, has not 

 as yet received from naturalists much attention. It may, however, be 

 advanced as certain that this molluscous animal most abounds in the 

 higher latitudes of both hemispheres, which would therefore seem to 

 be the places in which it is produced, and to which its habits are best 



