NICK RIBSAM might well be puzzled. Just ahead and on his right was the most enchanting natural spring of water that he had ever beheld. It was circular in shape, fully two yards in diameter and ten or twelve inches deep in the middle. From several places on the bottom the water bubbled up in a way that tumbled the sand in miniature fountains, which hid the current flinging the particles upward from below.

This basin was so clear that at first sight one was doubtful whether there was any water there at all; but the bubbling sand and the vigorous stream flowing away and across the trail, and losing itself among the rocks and vegetation, removed all question on that point.

The spring was partly shaded by a black bowlder leaning so far over that it seemed on[124] the point of tumbling in, while the scene in the immediate vicinity was rougher than any through which they had passed since crossing the ridge.

Domestic as well as wild animals are quick to discern the presence of water, and Nick had seen proof in the actions of Jack that he knew he was near the spring, some time before he himself knew it. The three were so pleased that they hastened their pace, and crowded their noses into the cool element, of which they drank with an enjoyment beyond description.

The youth meant to have a deep refreshing draught himself, but he had not the heart to check the ponies. He could wait better than they; they were not unclean animals, and the spring would quickly free itself of all traces of the contact with their silken noses.

But while Jack was stretching his head downward and standing with one fore leg bent at the knee, the better to reach the water, his rider prepared to give the call for Herbert to join him, when he was taken all aback by catching precisely the same signal from his friend.

[125]

There could be no mistake about it: he had heard it too often to confound it with any other sound.

He had noticed, while riding along the trail, that the divergence became more pronounced, thus separating him from Herbert by a greater distance than he had anticipated. As nearly as he could judge from the whistle, his friend was nearly, if not quite an eighth of a mile away, and between them the slope was so filled with rocks, bowlders, and stunted vegetation that travelling with a horse was out of the question. A trained mountaineer would find the task anything but an easy one. Herbert, therefore, must turn squarely about, and ride back to the fork in the trail, thus travelling double the distance made by Nick and the pack horses.

A moment’s reflection convinced the latter that Herbert had made a natural mistake. The stream, winding its way in that direction, probably formed a pool near the other part, so large and clear and beautiful that the youth mistook it for the spring itself.

“But he will see his error,” reflected Nick,[126] sending out the ringing blast by which he had summoned his friend many a time; “he doesn’t like to own up, but, when he looks upon this, he can’t help himself.”

Nick was convinced that there were few such natural springs in that section of Texas, though similar ones are found in plenty further east and among some of the mountainous portions.

The horses having had their fill, stepped back, and Nick began his preparations for spending the night. Everything was taken from the backs and heads of the animals and placed in a pile on the ground near at hand, while they were left to crop the grass, which was green and quite luxuriant in the vicinity of the stream.

By the time everything was complete, darkness had come. The animals were not tethered, for there was little to be feared of their running away, unless interfered with by outsiders, of which no one dreamed.

Nick now began to look for the coming of Herbert. Both paths were so easily travelled that he ought to appear in the course of[127] twenty minutes, and a full half hour had gone by.

“I wonder whether anything could have happened to him,” said Nick, gazing down the trail in the gathering gloom, and feeling a renewal of the fears that troubled him so much in the afternoon.

He once more whistled with the power of a steam engine, and paused for the response. It was impossible, as he had learned long before, that Herbert should have made his way on horseback across the space separating the t............