Abnormal foreshortening.
Contradictions and denials.
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, perspective 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 aërial 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.
Deceptive distances.
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 caution. 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 and look at the valley beyond it, the distance across might seem very slight. You can easily see to where another mountain range begins and trails away into the distance. Perhaps you fancy a few hours’ ride will take you over that valley-plain to where the distant foot-hills are lying soft and warm at the bases of the mountains. You may be right and then again you may be wrong. You may spend two days getting to those foot-hills.
Dangers of the desert.
Immensity of valley-plains.
This deception of distance is not infrequently accompanied by fatal consequences. The inexperienced traveller thinks the distance short, he can easily get over the ground in a few hours. But how the long leagues drag out, spin out, reach out! The day is gone and he is not there, the slight supply of water is gone and he is not there, his horse is gone and he himself is going, but he is not there. The story and its ending are familiar to those who live near the desert, for every year some mining or exploring party is lost. If there are any survivors they usually make the one report: “The distance seemed so short.” But there are no short distances on the desert. Every valley-plain is an immense wilderness of space.
Shadow illusions.
Color-patches on mountains.