THE DESEET 



air most distinctly. Very beautiful are these 

 Sunshafts golden sunshafts shot through the canyons. 

 canyons. And the red shafts are often startling. It 

 would seem as though the canyons were packed 

 thick with yellow or red haze. And so in real- 

 ity they are. 



There is one marked departure from the uni- 

 form warm colors of the desert that should be 

 mentioned just here. It is the clear blue seen 

 in the shadows of western-lying mountains at 

 sunset. This colored shadow shows only when 

 there is a yellow or orange hued sunset, and it 

 is produced by the yellow of the sky casting its 

 complementary hue (blue) in the shadow. At sea 

 a ship crossing a yellow sunset will show a mar- 

 vellous blue in her sails just as she crosses the 

 line of the sun, and the desert mountains re- 

 peat the same complementary color with equal 

 facility and greater variety. It is not of long 

 duration. It changes as the sky changes, but 

 maintains always the complementary hue. 



The presence of the complementary color in 

 the shadow is exceptional, however. The shad- 

 ows cast by such objects as the sahuaro and the 

 palo verde are apparently quite colorless ; and 

 so, too, are the shadows of passing clouds. The 

 colored shadow is produced by reflection from 



Comple- 

 mentary 

 kites in 

 shadow. 



Colored 

 shadows, 



