THE VOICE OF THE DESERT 



20 



many times a moisture-laden mass of air reaches as far as 

 these closest mountains. Dark clouds form, sometimes the 

 whole range is blotted out. Torrential rains are falling. But 

 on me not a drop. Either the sky is blue overhead or the 

 high clouds which have blown my way dissolve visibly 

 as the warm air rising from my sun-drenched flats reaches 

 them. I am in what the geographers call a "rain shadow" 

 cast by the mountains. Up at their summit the rainfall is 

 nearly twice as much as it is down here and they are 

 clothed with pines beginning at six or seven thousand 

 feet and going on up to the nine-thousand-foot peak. 

 When I do get rain in midwinter and in midsummer, it 

 is usually because winds have brought moisture up from 

 the Gulf of Mexico by an unobstructed southern^ route, 

 or because in summer a purely local thundershower has 

 been formed out of the hot air rising from the sun-beaten 

 desert floor. Most of the time the sun is hot, even in win- 

 ter, and the air is usually fantastically dry, the relative 

 humidity being often less than ten. 



Naturally the plants and animals living in such a region 

 must be specially adapted to survive under such condi- 

 tions, but the casual visitor usually notices the strangeness 

 of the landscape before he is aware of the flora or the 

 fauna. And the peculiar features of the landscape are also . 

 the result of dryness, even in ways that are not immedi- 

 ately obvious. 



The nude mountains reveal their contours, or veil them 

 as lightly as the late Greek sculptors veiled their nudes, 

 because only near the summits of the mountains can any- 

 thing tall enough to obscure the outlines grow. A little 

 less obvious is the fact that the beautiful "monuments" of 



