CHAPTER V. _Light, Air, and Color._--Popular ideas--Sunlight on

desert--Glare and heat--Pure sunlight--Atmospheric envelope--Vapor particles in air--Clear air--Dust particles--Hazes--Seeing the desert air--Sea-breezes on desert--Colored air--Different hues--Producing color--Refracted rays--Cold colors, how produced--Warm colors--Sky colors--Color produced by dust--Effect of heat--Effect of winds--Sand-storms--Reflections upon sky--Blue, yellow, and pink hazes--The dust-veil--Summer coloring--Local hues--Greens of desert plants--Color of the sands--Sands in mirage--Color of mountain walls--Weather staining--Influence of the air--Peak of Baboquivari--Buttes and spires--Sun-shafts through canyons--Complementary hues in shadow--Colored shadows--Blue shadows upon salt-beds--How light makes color--Desert sunsets 77