4,4:2 THE PHYSICAL GEOGRAPHY OF THE SEA. 



South — Observations, 8410; gales, 1228; rains, 1105 



North— " 526; " 135; " 64 



Gales to the 1000 obsei-vations . . S. 146 ; N. 256 



Rains " " . . S. 131 ; K 121 



That is, for every 10 gales, there are in the southern hemisphere 

 9 rains, and in the northern 4.7. In which hemisphere does most 

 water fall on the average during a rain at sea ? Observations do 

 not tell, but there seems to be a philosophical reason why it should 

 rain not only oftener, but more copiously at sea, especially in the 

 extra-tropical regions, in the southern hemisphere than in those 

 of the northern. On the polar side of 40° N., for example, the 

 land is stretched out in continental masses, upon the thirsty bosom 

 of which, when the air drops down its load of moisture, onty a 

 portion of it can be taken up again ; the rest is absorbed by the 

 earth to feed the springs. On the polar side of 40° S. we have 

 a water instead of a land surface, and as fast as precipitation takes 

 place there, the ocean replenishes the air with moisture again. It 

 may consequently be assumed that a high dew-point — at least one 

 as high as the ocean can maintain in contact with winds blowing 

 over it, and going from warmer to cooler latitudes all the time — ^is 

 the normal condition of the air on the polar side of 40° S., where- 

 as on the polar side of 40° N. a low dew-point prevails. The 

 rivers to the north of 40° could not, I reckon, if they were all 

 converted into steam, supply vapor enough to make up this aver- 

 age difference of dew-point between the two hemispheres. The 

 symmetry of the rain and storm curves on the polar side of 40° 

 S. suggests that it is the condensation of this vapor which, with 

 the liberation of its latent heat, gives such activity and regularity 

 to the circulation of the atmosphere in the other hemisphere. 



827. On the polar side of 40° S., near Cape Horn, the gauge of 

 Th! rain-fall of Cape Captaius Kins" aud Fitzrov showed a rain-fall of 



llirn and Cherra- ^ . , . , ^ ^r,, 



ponjio. 153. / 5 inches m 41 days. There is no other place 



except Cherraponjie where the precipitation approaches this in 

 amount. Cherraponjie (§ 299) is a mountain station in India, 

 4500 feet high, which, in lat. 25° N., acts as a condenser for the 

 monsoons fresh from the sea. But on the polar side of lat. 45°, in 

 the northern hemisphere, it is, except along the American shores 

 of the North Pacific, a physical impossibility that there should be 

 a region of such precipitation as King and Fitzroy found on the 



