CHAPTER XV 



DESERTS 



In consequence of the world's rotation, there are certain 

 latitudes in which the winds blow in a more or less definite 

 direction almost the whole year through. When the 

 trend of the coast-line is such that these winds are off- 

 shore or parallel to the coast, no rain reaches the land. 



This explains, e.g., the nitrate deserts of Chile, the 

 Namaqualand and Kalahari deserts in Africa, a small 

 patch of very dry country in South Madagascar, and the 

 West Australian desert. 



These, however, are but small as compared with those 

 of the Northern hemisphere, and especially the great 

 Saharan-Central Asian desert which extends from the 

 Atlantic to the borders of British India. 



That this world is aged and drying up is by no means 

 a new theory. It was a favourite subject for discussion 

 with such ingenious scientists as Dr. Maillet and Celsius. 



Prince Krapotkin and others consider that, in our own 

 geological period, the world is rapidly drying up, and 

 that Asia in particular is becoming far more desert than 

 it used to be. 1 It is of course indisputable that, for in- 

 stance, the arid and desolate plains of Jungaria were 

 once full of inhabitants. Dr. Sven Hedin discovered 

 ruins of cities once wealthy and luxurious, with rich 

 monasteries and evidence of once carefully irrigated 

 fields in Teklamakan, which is now a desert of sand, 

 so destitute of water and of forage that that intrepid 

 explorer had the greatest difficulty in traversing it. 



Still this does not necessarily prove that there is no 



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