110 PHYSICAL GEOGRAPHY OF THE SEA, AND ITS METEOROLOGY. 



rents in the mountains, and the clouds gradually overspiead the 

 whole sky. But for the wind, which again springs up, it would 

 be alarming to the sailor, who is helpless in a calm. ^Vhat 

 change will take place in the air? The experienced seaman, 

 who has to work against the trade-wind or against the monsoon, 

 is off the coast, in order to take advantage of the land breeze (the 

 destroyer of the trade) so soon as it shall come. lie rejoices 

 when the air is released from the land and the bieeze comes, at 

 first feebly, but afterward growing stronger, as usual during the 

 whole night. If the land breeze meets with a squall, then it is 

 brief, and becomes feeble and uncertain. We sometimes find 

 then the permanent sea breeze close to the coast, which otherwise 

 remains twenty or more English miles from it. One is not 

 always certain to get the land breeze at the fixed time. It some- 

 times suffers itself to be waited for ; sometimes it tarries the 

 whole night long. During the greatest part of the rainy season,, 

 the land breeze in the Java Sea cannot be depended upon. This 

 is readily explained according to the theoiy which ascribes the 

 origin of the sea and land breezes to the heating of the soil by 

 day, and the cooling by means of radiation by night ; for, during 

 the rainy season, the clouds extend over land and sea, interrupt- 

 ing the sun's rays by day and the radiation of heat by night, 

 thus preventing the variations of temperature ; and from these 

 variations, according to this theory, the land and sea breezes 

 arise. Yet there are other tropical regions where the land and 

 sea breezes, even in the rainy season, regularly succeed each 

 other." 



317. Sanitary hiflueuces of land and sea breezes. — One of the causes 

 which make the west coast of Africa so very unhealthy when 

 compared with places in corresponding latitudes on the opposite 

 side of the Atlantic, as in Brazil, is no doubt owing to the differ- 

 ence in the land and sea breezes on the two sides. On the coast 

 of Africa the land breeze is " universally scorching hot."* 

 There the land breeze is the trade-wind. It has traveised the 

 continent, sucking up by the way disease and pestilence from 

 the dank places of the interior. Keeking with miasm, it reaches 

 the coast. Peru is also within the trade-wind region, and the 

 winds reach the west coast of South America, as they do the west 

 coast of Africa, by an overland path ; but, in the former case, 

 instead of sweeping over dank places, they come cool and fresh 



* Jansen. 



