A word concerning the Ciboleros may not be uninteresting.  Every year, large parties of Mexicans, some with mules, others with ox-carts, drive out into these prairies to procure for their families a season’s supply of buffalo beef.  They hunt chiefly on horseback, with bow and arrow, or lance, and sometimes the fusil, whereby they soon load their carts and mules.  They find no difficulty in curing their meat even in midsummer, by slicing it thin, and spreading or suspending it in the sun; or, if in haste, it is slightly barbecued.  During the curing operation, they often follow the Indian practice of beating the slices of meat with their feet, which they say contributes to its preservation.

Here the extraordinary purity of the atmosphere of these regions is remarkably exemplified.  A line is stretched from corner to corner along the side of the waggon body, and strung with slices of beef, which remain from day to day till they are sufficiently cured to be packed up.  This is done without salt, and yet the meat rarely putrefies.

The optic deception of the rarefied and transparent atmosphere of these elevated plains is truly remarkable.  One might almost fancy oneself looking through a spy-glass; for objects often appear at scarce one-fourth of their real distance—­frequently much magnified, and more especially much elevated.  I have often seen flocks of antelopes mistaken for droves of elks or wild horses, and when at a great distance, even for horsemen; whereby frequent alarms are occasioned.  A herd of buffaloes upon a distant plain often appear so elevated in height, that they would be mistaken by the inexperienced for a large grove of trees.

But the most curious, and at the same time the most tormenting phenomenon occasioned by optical deception, is the “mirage,” or, as commonly called by the Mexican travellers, “the lying waters.”  Even the experienced prairie hunter is often deceived by these, upon the arid plains, where the pool of water is in such request.  The thirsty wayfarer, after jogging for hours under a burning sky, at length espies a pond—­yes, it must be water—­it looks too natural for him to be mistaken.  He quickens his pace, enjoying in anticipation the pleasures of a refreshing draught; but, as he approaches, it recedes or entirely disappears; and standing upon its apparent site, he is ready to doubt his own vision, when he finds but a parched sand under his feet.  It is not until he has been thus a dozen times deceived, that he is willing to relinquish the pursuit, and then, perhaps, when he really does see a pond, he will pass it unexamined, from fear of another disappointment.

The philosophy of these false ponds I have never seen satisfactorily explained.  They have usually been attributed to a refraction, by which a section of the bordering sky is thrown below the horizon; but I am convinced that they are the effect of reflection.  It seems that a gas (emanating probably from the heated earth and its vegetable matter) floats upon the elevated flats, and is of sufficient density, when viewed obliquely, to reflect the objects beyond it; thus the opposing sky being reflected in the pond of gas, gives the appearance of water.