440 PHYSICAL GEOGllAPHY OF THE SEA, AND ITS METEOROLOGY. 



oilier there is but little land and loss snow. On the Y)olar side 

 of 40^ S. especially, if we except the small remnant of this con- 

 tinent that protrudes beyond that parallel in the direction of 

 Oape Horn, tliere is scarcely an island. All is sea. There the 

 air is never dry ; it is always in contact with a vapour-giving 

 surface ; consequently, the winds there arc loaded with moisture, 

 which, with every change of temperature, is either increased by 

 farther evaporation or diminished by temporary condensation. 

 The propeUiruj power of the winds in the southern hemisi^here resides 

 chiefly in the latent heat of the vapour ivhich they such up from the 

 engirdling sea on the polar side of Capricorn. 



824. Lieut. Van GougWs Storm and Main Charts. — The Storm 

 and Iiain Charts show that within the trade-wind regions of both 

 hemispheres the calm and rain curves are symmetrical ; that in 

 the extra-tropical regions the symmetry is between the calm and. 

 ■fog curves; and also, especially in the southern hemisphere, 

 between the gale and rain curves. Lieutenant Van Gough, of 

 the Dutch Navy, in an interesting paper on the connection be- 

 tv/een storms near the Cape of Good Hope and the temperature 

 of the sea,* presents a storm and rain chart for that region. It is 

 founded on 17,810 observations, made by 500 shij)s, upon wind 

 and weather, between 14° and 32° E., and 33° and 37° S. By 

 that chart the gale and rain curves are so symmetrical that the 

 phenomena of rains and gales in the extra- tropical seas present 

 themselves suggestively as cause and effect. The general storm 

 and rain charts of the Atlantic Ocean, prepared at the National 

 Observatory, Washington, hold out the same idea. Let us 

 examine, expand, and explain this fact. 



825. The " hrave west winds" caused hy rarefaction in the antarctic 

 r^egions. — We ascribe the trade-winds to the equatorial calm-belt. 

 But to what shall we ascribe the counter-trades, particular!}- of 

 the southern hemisphere, which blow with as much regularity 

 towards the pole as the north-east trades of the Atlantic do 

 towards the equator ? Shall we say that those winds are drawn 

 towards the south pole by heat, which causes them to expand and 

 ascend in the antarctic regions? It sounds somewhat para- 

 doxical to say that heat causes the winds to blow towards the 

 poles as well as towards the equator ; but, after a little explana- 

 tion, and the passing in review of a few facts and circumstances, 



* De Stormen nabij de Kaap de Goede Hope in verband bescliouwd met de 

 "tl'omperatuur der Zee. 



