ILLUSIONS 



113 



of the gray-based mountain, which has been 

 puzzling you for so many hours, does not be- 

 long to the gray base at all. It is a pine-clad 

 top resting upon another and more massive base 

 far back in the group. It is the highest and 

 most central peak of the range. 



Such illusions are common, easily explained ; 

 and yet, after all, not so easily understood. They 

 are caused by false perspective, which in turn 

 is caused by light and air. On the desert, per- 

 spective is always erratic. Bodies fail to detach 

 themselves one from another, foreshortening is 

 abnormal, the planes of landscape are flattened 

 out of shape or telescoped, objects are huddled 

 together or superimposed one upon another. 

 The disturbance in aerial perspective is just 

 as bad. Colors, lights, and shadows fall into 

 contradictions and denials, they shirk and bear 

 false witness, and confuse the judgment of the 

 most experienced. 



No wonder amid this distortion of the natural, 

 this wreck of perspective, that distance is such 

 a proverbially unknown quantity. It is the one 

 thing the desert dweller speaks about with cau- j 

 tion. It may be thirty or fifty miles to that 

 picacho he is afraid to hazard a guess. If you 

 should go up to the top of your mountain range 



False per- 

 spective. 



Abnormal 

 foreshort- 

 ening. 



Contradic- 

 tions and 

 denials. 



Deceptive 

 distances. 



