OCEANIC CONTROL OVER CLIMATE 41 



drought one year, and by a deluge the next. 

 It is no consolation to a farmer to tell him that 

 the average total of his rainfall is an ideal 

 quantity, if his average of 25 inches is made up 

 of a drought of 5 inches one year, and a 

 destructive deluge of 45 inches the next. The 

 agriculturist is more interested in the natural 

 inconstant weather than in the artificial in- 

 constant climate. Such factors as the 

 alternation of summer and winter, and the 

 positions of the oceans and continents do not 

 explain the variations of the weather from year 

 to year, because being fixed, they should 

 have always the same effect. If, as was once 

 thought, ocean currents flowed on fixed and 

 permanent courses, like rivers on the land, then 

 their effects upon the climate of the adjacent 

 lands should also be unchanging ; but as the 

 air circulation varies with the seasons, it is only 

 natural that the oceanic circulation should also 

 vary at different times of the year ; and, what 

 is still more important, there is now abundant 

 evidence to prove that the oceanic circulation 

 also varies from year to year. 



The Valdivia and the Challenger found the 

 oceanic circulation of the Southern Ocean south 

 of Kerguelen was very different at the time of 

 their visits. As Dr. Schott put it, ." the well- 

 known series of temperatures observed by the 

 Challenger in the south of Kerguelen towards 

 the ice-limit, has not been found by us, perhaps 

 because the Valdivia was not far enough to the 



