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."

"But you must pay attention to such things, and a good deal of it too,
if you are going to be a Plainsman. During the last two nights there has
been no dew at all. I noticed that some blades of grass, which had been
pressed down by the hoofs of the horses and cattle, were covered with
sand which stuck fast to them, having been dried on. This told me that
the tracks were made while the grass was wet, and that the Indians had
passed that way early on Thursday morning, or before the sun had risen
high enough to dry off the dew. There were not more than fifteen or
twenty of them. I didn't have time to see just how many, but they have
stolen over a thousand head of steers and horses. Now, r