"Because I saw their tracks," replied George.
"That's not explicit enough. I suppose you did see the tracks of the horses, and so did I; but how in the world is a fellow going to tell whether or not those horses had riders on their backs? That's something that can't be done."
"Don't be too sure of that. Look here! Would you believe it if I should tell you that those Indians passed along here after daylight on Thursday morning?"
"No, I wouldn't," replied Bob bluntly. He could not, for the life of him, understand how anybody could draw such conclusions as these by simply looking at the print of a pony's hoofs in the grass; and if he had not been so well acquainted with George he would have inclined to the belief that his friend was "spreading it on" in order to make himself out a wonderful trailer. "I can't make head or tail of this business, and I don't believe you can, either; that is, I mean I don't see how you can."
"Well, listen while I explain," said George good-naturedly. "In the first place, I noticed, while we were passing through that belt of post-oaks back there, that some of the horses left a very devious trail, passing through thick bushes and under trees whose branches were so low that they would have swept a rider out of his saddle if he had not been on the alert to avoid them. Those horses were all loose."
"Perhaps not," exclaimed Bob. "The Indians might have passed through there when it was too dark to see where they were going."
"I know they might, but they didn't, as I shall presently show you. The horses which made those crooked trails were not mustangs. They were American horses, and their presence proves another thing that I didn't think to speak of before; and that is, that the Indians raided other ranches besides Mr. Wentworth's. How do I know that they were American horses? Because their tracks were larger than a pony's, and some of them were shod. The tracks made by the mustangs led through the open part of the timber, where there were no bushes and low branches; and this is one proof that the Indians did not pass through there in the night-time. If they had, they could not have kept in such open ground. I found further proof that these mustangs were all mounted by noticing that they did not stop to graze, as the loose horses did, being kept in constant motion by their riders. What do you think now?" asked George, seeing that Bob began to open his eyes.
"It reads like a book, don't it?" was Bob's reply. "But you have forgotten one very important thing. You said that the Indians passed through those post-oaks early on Thursday morning. How do you know that they didn't pass late on Thursday afternoon or early on Friday morning?"
"You think you have got me there, don't you? Well, you haven't. If there are 'sermons in stones and books in running brooks,' as the poet tells us there are, what is the reason that the print of an Indian pony's hoof may not contain a page of information that will prove to be useful to him who has the skill to read it? On Wednesday night there was a very heavy dew, if you remember."
"I don't remember," replied Bob; "I never pay any attention to such things."