My companions knew the landmark well. It lay directly in our route. We should pass near its base, and a ride of ten miles farther would bring us to the end of our journey; indeed, the eminence was within sight of the rancheria. From the roof of the alcalde’s house I had frequently noticed it outlined against the horizon, in a north-westerly direction from the village. In clear weather only was it visible.
Struck with the singularity of this prairie-mound, I had longed to examine it, and had even projected a visit to it; but circumstances had prevented me from carrying out my intention. I was at length to have the pleasure of a nearer acquaintance with it.
I have called it singular. Most isolated hills are conical, dome-shaped, or ridge-like; this one differed from the usual configuration—hence its singularity. It presented the appearance of a huge box set upon the prairie, not unlike that rare formation, the “cofre,” which crowns the summit of the mountain Perote. Its sides in the distance appeared perfectly vertical, and its top horizontal as the plain on which it rested.
As we drew nearer, I could perceive by the dark parapet-like band along its crest that it was covered with a growth of timber. This was the more readily observed from contrast with the perpendicular sides, which were almost of a snowy whiteness, on account of the gypsum, chalk, or milky quartz of which the rock was composed.
The most peculiar feature of the mound was perhaps its apparently regular form—a perfect parallelopipedon. But it was striking in other respects. Its sides glistened fantastically under the rays of the sun, as though it were studded with settings of glass. This, however, was easily accounted for; and I knew that the sparkling effect was produced by plates of mica or selenite that entered into the composition of the rock. I had seen large mountains that presented a similar appearance. More than one such exist in the great American Saara, in whose glittering cliffs, viewed from afar, may be found the origin of that wild chimera, the mountain of gold.
Although neither a mountain of gold nor silver, the mound in question was an object of rare interest. A very enchanted castle it did appear, and it was difficult to assign its formation to nature alone. Human agency, one could not help fancying, must have had something to do in piling up a structure so regular and compact.
But he who has travelled over much of the earth’s surface will have met with many “freaks” of nature, exhibiting like appearance of design, in her world of inorganic matter. It was, in fact, one of those formations, of which many are met with in the plateaux-lands of America, known in Spanish phraseology as mesas. This name is given to them in allusion to the flat table-like tops, which distinguish them from other elevated summits.
Sometimes one of these mesas is found hundreds of miles from any similar eminence; more frequently a number of them stand near each other, like truncated cones—the summits of all being on the same level, and often covered with a vegetation differing materially from that of the surrounding plains.
Geologists have affirmed that these table-tops are the ancient level of the plains themselves; and that all around, and intervening between them, has either sunk or submitted to the degradation of water!
It is a vague explanation, and scarcely satisfies the speculative mind. The mesa of Mexico is still a geological puzzle.