WINDS 



8i 



the Equator, while in summer it is about or lo degrees north 

 latitude, and, as will be explained later, the tropical rains of certain 

 regions depend upon this movement. Their easterly direction is 

 due to the rotation of the world. 



Periodical winds are the movements of the air produced by the alternate 

 heating (by the sun) and cooUng of large tracts of lands, and the most important 

 of these are the monsoons, to which reference has already been made. 



Variable winds are found in the regions of calms interposed between the 

 trades in the Atlantic and Pacific Oceans. 



Local winds are of great importance in the tropics, constituting the so- 

 called land wind, sea breeze, mountain wind, etc., and several others to be 

 referred to later, to which special local names have been given. 



The wind about which a great deal is spoken in every tropical country is 

 the land wind,' During the day the land becomes heated by the sun, and 

 causes the air to rise, thus lessening the pressure, and drawing the air from the 

 sea, causing a sea breeze, which is, of course, very humid. During the night, 

 however, by terrestrial radiation, the land becomes cooler than the sea, and 

 the air travels from the land to the sea, and constitutes the land wind. This 

 wind, as a rule, is dry, and has a very deleterious effect on men and animals 

 by extracting moisture and abruptly cooling the body, and thereby lowering 

 the resisting-power to disease. Hence the complaints made by old residents 

 about the land breezes. On the other hand, new-comers delight in them, 

 because they are so cool. 



This land wind is more marked at certain seasons of the year than at others, 

 being particularly felt in Colombo in those months when there is less cloud, 

 because the terrestrial radiation is then more marked. There is, however, 

 nothing like a definite season for a pronounced land wind, for it can take place 

 at any time, only depending upon terrestrial radiation. 



A few remarks may be useful with regard to some local winds : — • 



The Sirocco (Italian, scirocco). — The sirocco is a south-east wind with a 

 high temperature, which, coming from the high land of North Africa, descends 

 to the Mediterranean, and may reach Malta and some parts of Italy. It is 

 considered to be very enervating. 



The Solano. — The solano is a south-easterly wind, blowing from the Sahara 

 into Spain. 



The Harmattan. — The harmattan is a hot easterly wind, coming from the 

 Sahara Desert, and carrying dust far out into the Atlantic 



In the months of November to March this wind meets with the north- 

 east trade in its most southerly position, with the result that it is deflected 

 southwards down the west coast of Africa. It is a very dry wind, and there- 

 fore extracts moisture from everything it comes across. Hence human beings 

 feel their skin dry and hard, and may suffer from bleeding from the nose 

 and lips, while furniture creaks and groans in a most supernatural manner. 



The Khamsin. — The khamsin, or khamseen, is the dust-laden wind which 

 blows from the Sahara into Egypt at intervals during fifty days about Easter- 

 time, and is very disagreeable, especially when associated, as it often is, with 

 high air temperatures, when it may produce pathological changes in persons 

 in poor health situate in places unsuitable for bearing heat, such as railway 

 trains. 



Pamperos. — These are the south-westerly winds of Brazil. Europeans have 

 altered the significance of the name to squally cyclonic winds in the same 

 vicinity. 



Ghibli. — -The ghibli is a violent south or south-east wind blowing into 

 Tripoli from the desert, and carrying with it a quantity of sand, which causes 

 irritation to the conjunctivae and which may induce nervous symptoms. 



The Foehn. — Though essentially a temperate or cool climate wind, still the 

 foehn exists in the tropics. The foehn is to be seen in its home, Switzerland, 

 as a warm dry wind which blows with great violence downwards from the crest 

 of the Alps, and has marked effects upon man and animals, as it has a depress- 

 ing effect upon the mind and the nervous system. It was thought at one 



