CHAPTER XXXIII.

WONDERFUL MIRROR OF THE PLAIN.

“Buffler, what d’ye make out o’ thet mirrij?”

Old Nomad had aroused the scout very early to look at the sky, which reflected the plain for miles.

The pards had camped the previous evening in a basin in the broken clay of the Bad Lands where the rains had formed a miniature lake, around which grass had started up luxuriantly. The place resembled an immense “buffalo wallow” and had all the appurtenances in the way of “buffalo flies” which at first threatened to drive the thin-haired horses into a stampede, when the party first arrived late in the afternoon. But a flock of starlings came soon after and, alighting on the horses, soon put the flies to rout.

Cayuse had stumbled upon the place in the afternoon and it was decided to remain where there was good grazing and plenty of water, although the latter was not an attractive quality.

Hidden from the surrounding country, with the breeze sweeping across the pool, after the sun went down the pards found it to be a delightful camping ground.

They slept soundly, and although two-hour watches placed each, with the exception of Tootsie, on guard during the night, not the slightest cause for alarm was discovered.

It was old Nomad’s morning watch and he had finally awakened Buffalo Bill to study a beautifully clear mirage, which depicted a scene that puzzled the trapper.

The young reader may not know that the phenomenon referred to is extremely common in some localities, and due to atmospheric conditions. It is usually caused by a diminution of the density of the air near the surface of the earth, often produced by the radiation of heat, the denser stratum being thus above instead of below the rarer, which latter is the usual case. Now, rays of light from a distant object, situated in the denser medium--that is, a little above the earth’s level--coming in a direction nearly parallel to the earth’s surface, meet the rarer medium at a very obtuse angle, and instead of passing into it, they are reflected back to the dense medium, thus acting as a mirror.

The image produced by the reflected rays will appear inverted, and below the real object, just as an image reflected in the water appears when observed from a distance. The phenomena are frequently much more strange and complicated, the images being often much distorted and magnified, and in some instances occurring at a considerable distance from the object, as in case of a church seen over the sea or an inverted vessel sailing over the land. If the object is a cloud, or portion of sky, it will appear by the reflected rays as lying on the surface of the earth and bearing a strong resemblance to a sheet of water; also, as the reflecting surface is irregular, and constantly varies in position, owing to the constant communication of heat to the upper stratum, the reflected image will be constantly varying, and will present the appearance of a water surface ruffled by the wind.

Thus in the deserts of lower Egypt, Persia, Turkestan, and on the great Western plains of the United States, whole caravans have been led from the trail by thirst toward an inviting lake which appears to be but a few miles away. If the ground is favorable the mirage may be dispelled as the observer advances, but in others it is like an ignis fatuus, hovering ever in sight, but always beyond reach, until the victim succumbs to thirst and his body is left a monument to his own misunderstanding of one of nature’s most fascinating jokes.

Buffalo Bill came to the trapper’s side on the rim of the basin, where Nomad pointed to the southwest. The sky looked a lead-colored haze that held well down to the horizon, with a belt of clear blue underneath, but nearer, and seeming a few miles away, was a tracery in the heavens, apparently far below the clouds, of a vast map of the plain.

The buttes, and ravines, and gashes, the buffalo wallows, skulls, and clusters of weeds, were laid out across the sky with a variation of distinctness and color.

The distortions were surprising, the images coming suddenly nearer or fading away in the distance. A little brook suddenly grew to a great river and objects seemed to be moving on its surface.

But more surprising than all the rest was the mirrored outline of a crack in the hard-baked surface of the plain. Reflected there in the peculiar morning sky, the crevice looked to be several feet wide and running for a long distance in a direction that allowed the smaller or farther end to fade out and disappear in the distance, while the nearer approached diagonally until it appeared scarcely half a mile away, ending in the side of a strangely marked butte.

This latter, seen top down in the sky, appeared hollow, surrounded by a high, square-topped wall. And the centre of the hollow reflected green.

Down the crevice toward the butte some object was moving. Sometimes it came out clearly, enormously magnified by the variation of heat radiation, and would seem about to be distinctly revealed in every detail to the observer; then its brilliancy would fade.

On the whole, the moving object looked like some gigantic worm crawling along the rut made by a narrow-rimmed wheel. The reflection gave no detail below the ground level, because of a different layer of air there, but moving along the centre of this outlined crevice was the bobbing, disappearing, and reappearing object.

“Don’t that git yer guessworks clogged, Buffler?” said Nomad, after a period of silent observation.

“It certainly is a puzzler; call the rest of the boys and see what they think of it.”

Before the mirage had faded the pards had seen the crawling thing reach the mirrored butte and disappear.

“That’s not in the direction we travel,” said Hickok, “but I move we go out of our way a few miles to see if that picture was painted true.”

“I second ther motion,” said Nomad.

“It is moved and approved that we make a tour of investigation to satisfy our own curiosity,” said Buffalo Bill. “If that be your minds you will so vote.”

All raised their hands and answered “Ay.”

Breakfast was prepared and eaten and then the pards set off on a mission of inquisitiveness which led to one of the strangest adventures that ever befell either of the famous scouts.

While the mirrored picture of the gash and butte represented the scene as not more than half a mile distant, after a ride of an hour the pards had seen nothing that looked like it. They had hardly expected to find the place much sooner and perhaps not at all, for, with the exception of Tootsie, they were familiar with the false reports of nature’s news sheet.

Another hour and they had paused on the crest of one of the great prairie waves to study the surroundings, when Buffalo Bill, who was using a field glass, uttered an exclamation of surprise.

The scout handed the glass to Wild Bill, who said:

“By gorry!”

Nomad reached for the glass and alter a moment’s study of a distant butte, let loose with:

“Waal, by ther ring-tailed, rip-snortin’ heifercats! Wouldn’t thet make ye swaller yer gum?”

It was Skibo’s turn, and after a moment the giant black man handed the glass to Tootsie and turned to Buffalo Bill.

“Mars’ Billyum,” he said, “yer goin’ sabe de lil’ missy if it takes de las’ piece ob meat f’m ole Skibo’s bones to do it--ain’t dat so, Mars’ Billyum?”

“She sees us and seems to think we are Indians, for she is running along the top of the mesa and now she drops out of sight!” cried the boy excitedly.

The cause of the exclamations by the scout and his pards was the sight of a girl, or young woman, with long yellow hair floating in the wind, standing on the top of a high, perpendicular-sided butte, and, apparently, studying the landscape by peering under her hand.

The butte on which the girl stood seemed above its surroundings and alone. Not a wrinkle on the surface about it showed at that distance, but far beyond could be seen the sheen of a river, with bushes and little bunches of timber along its banks.

“Mebbe she’s a angel, but I didn’t notice any wings,” mused Nomad, staring in that direction, although with the naked eye he failed to see the picture on the bluff.

“Yah, yah! Ah reckons she mus’ hab wings, ter hab flewed so high to roost,” remarked Skibo.

“Probably the other side of the butte is scalable,” observed Wild Bill, “but if a maiden is lost or hiding from Indians, we ought to rescue her.”

“That is right, Hickok,” said the scout, “but----” He hesitated. Buffalo Bill was thinking of the mirage of the morning. There was the butte of the same contour as the one mirrored in the sky. The crevice did not show, but he believed it would be visible, on nearer approach.

“But what, Buffler?” asked Nomad.

“I think we have discovered all we shall of this mystery unless we spend a lot of time on it,” quietly answered the scout.

“That is just what I was thinking,” said Wild Bill.

“Ye don’t think this hyar kentry is _muy malo_, do ye?” queried Nomad.

“No, Nomad; I think the country is all right, but I’ll wager that there is some deep mystery in this case of a girl on the apex of a pinnacle in the middle of the wildest country in the Northwest.

“We will investigate as far as practicable at this time, and, if we do not reach an explanation readily--as I do expect we shall--we must ride on and attend to our duties first; then if we care to come back here to unravel a mystery, that will be our privilege.”

“Righto!” chirped Wild Bill, “but suppose we toddle on the base of the bluff and look around it? That will not occupy much time.”

They were obliged to advance more or less cautiously because of the broken nature of the footing, seams and chasms running hither and thither, like rivulets after a shower.

At last at the base of the isolated butte, which was much larger and higher than it appeared from the distance, the pards found it to be a precipitous wall of more than one hundred feet from base to top of the main cone, and this was surrounded by a massive foot-piece more than half as high and three times as broad.

By difficult climbing and jumping wide and deep crevices, they at last attained the top of the base rock, which was as level as a house floor and formed a plateau of probably two hundred acres. Out of the centre of this arose the shaft first seen, towering scores of feet above them, an apparently solid block of rock, smaller in circumference at the base than at the top, as smooth and as impossible of ascent as the outer surface of Bunker Hill monument.

It was on the top of this block, which was perhaps sixteen hundred feet in circumference or five hundred feet in diameter, that they had seen a human being.

“’Member what I said erbout angels?” asked Nomad, staring up dizzily at the top, which seemed wavering against the sky.

“Mars’ Billyum, Ah reckons ’twouldn’t do no harm ’f Ah should jes’ holler a few words o’ United States so’s de lil’ missy won’t t’ink we’s Injuns,” suggested Skibo.

“I think there is no need of it, Skibo,” answered the scout, who, with head thrown back, had been studying the top of the rock.

As the scout spoke a hush fell over all the pards, for there had suddenly appeared on the very edge of the pinnacle a girlish figure quaintly dressed and looking down at them.

The scout and Wild Bill doffed their sombreros and the former shouted:

“Can we be of service to you, young lady?”

“No, sir; I think not. I am as free as the air and the birds, and care not for the ways of the world or its people.”

“Are you alone?” he asked.

“Why should you ask? If I am happy and need nothing of the world, why should it care whether I am alone or not? The dark-skinned people of the plain respect my desires and call me, in their tongue, the daughter of the moon. I go and come as I wish among them. But the dark-skinned people hate the white-skinned people and hope to drive them into the sea. Even now I can see, far across the plain, a large party of mounted warriors who come this way. If my white-skinned brothers remain here they will be slain or taken prisoners.

“Go that way”--and she pointed to the south and east. “Two miles on you will find a river. Follow it far and keep well to the timber, for on both sides the country swarms with red brothers who are hostile to the white brothers. Go! and tell the white people who ask, that I am the mystery of the lone rock.”

She disappeared, and the scout and his pards turned away as she had directed, but not until Buffalo Bill had discovered the crevice which the mirage had revealed, leading from far away toward the river to the base of the butte. He mistrusted that some hidden entrance led under the bluff to the hollow interior which the inverted cone had shown.