INTRODUCTORY 7 



of the common gray. But in course of ages this ma- 

 terial, lying usually in huge slabs, has taken on a 

 surface sheen and coloring due to weathering and 

 baking by the sun. It is spoken of as "desert glaze," 

 and is really something like the artificial glaze of 

 pottery. Even when the rocks take boulder form 

 they are generally great, house-like cubes or rhom- 

 boids, offering flat surfaces which sun and weather 

 have painted in the same broad, strong hue. Only 

 where cailons choked with more freshly shattered 

 rock score the mountain walls does one catch the 

 native tint of the granite, making a startling con- 

 trast. From these carion mouths wide, fan-like sheets 

 of similar debris sweep down to the level. Up these 

 the eye ranges, higher and higher, into gloomy gal- 

 leries and chasms until the thread is lost in a maze 

 of braided folds of mountain, these overlooked often 

 by some far, high crest, in winter white with snow, 

 in summer gray with iron crag and precipice of gran- 

 ite, but always softly clouded with humanizing pines. 

 The characteristic contour form of the desert 

 mountain ranges is another element in the beauty 

 of desert color. Like geological models set on a table, 

 they stand up sharply defined from the general 

 level, arresting the glance with new, conspicuous 

 effects. No gently modelled approaches prepare the 

 eye for the change of plane. From gray or drab ex- 

 panse of sand they rear up wall-like profiles of red 

 or ochre. Perspective is dwarfed by the clearness of 

 air, increasing the sense of verticality. Instead of 

 rising from the desert, these mountains stand upon 

 it, explicit, bald, almost artificial. 



