LIGHT, AIR, AND COLOR 



87 



gray-blue also. The yellow haze of the desert 

 is seen at its best when there is a yellow sunset, 

 and the pink haze when there is a red sunset, 

 indicating that at least the sky has some part 

 in coloring by reflection the lower layers of 

 desert air. 



Whatever the cause, there can be no doubt 

 about the effect. The desert air is practically 

 colored air. Several times from high mountains 

 I have seen it lying below me like an enormous 

 tinted cloud or veil. A similar veiling of pink, 

 lilac, or pale yellow is to be seen in the gorges 

 of the Grand Canyon ; it stretches across the 

 Providence Mountains at noonday and is to be 

 seen about the peaks and packed in the valleys 

 at sunset; it is dense down in the Coahuila 

 Basin ; it is denser from range to range across 

 the hollow of Death Valley ; and it tinges the 

 whole face of the Painted Desert in Arizona. 

 In its milder manifestations it is always present, 

 and during the summer months its appearance 

 is often startling. By that I do not mean that 

 one looks through it as through a highly colored 

 glass. The impression should not be gained 

 that this air is so rose-colored or saffron-hued 

 that one has to rub his eyes and wonder if he is 

 awake. The average unobservant traveller looks 



Blue, 



yellow, and 

 pink hazes. 



The dust- 

 veil 



Summer 

 coloring. 



