28 ANIMAL LIFE IN DESERTS 



are the windiest months of the year, 75 per cent, of 

 the wind, and an even higher proportion of the 

 stronger winds, are from this quarter. The sirocco 

 and the shamal are two examples of the strong 

 winds from a certain quarter, which blow with 

 regularity in many deserts, but other and more 

 violent regular winds are on record. 



At Menjil in North- West Persia a wind of great 

 violence and regular occurrence blows whenever the 

 sun is shining brightly on the Persian plateau. It 

 is caused by the rising of the air which has been 

 warmed by the hot plateau, and the consequent 

 inrush of unwarmed air from the surrounding areas. 

 At Menjil this is concentrated in the gorge of the 

 Safid Rud, a river which here cuts its way through 

 the Elburz Mountains, and a constant violent wind 

 blows through the gorge all the day long, throughout 

 the summer. This wind is of such strength that one 

 can only walk against it with the greatest difficulty, 

 and I have seen a loaded camel entirely unable to 

 make headway against it ; tents can only be pitched 

 during the hours of relative calm in early morning 

 and late evening, and when securely pitched are 

 generally ripped to shreds. Even more violent winds 

 have been experienced in many desert areas, but 

 few of them are of such regular occurrence as the 

 Menjil wind. Augieras, for example, has recorded 

 that in February, 1915, a violent wind kept him 

 prisoner under the lee of a rock at Erg Chech in the 

 Western Sahara for no less than nine days, and a 

 month later he experienced a gale which carried a 

 camel saddle 200 metres. The effect of wind-driven 



