He shifted his position a trifle, went through the motion of taking aim, looking down at his feet, then dropped his arms, and said:
"I can't do it; to aim at you there, I would have to stand just where you have left some bits of paper. In any other position the bushes obstruct the sight."
I came down to the gate and swung it open.
"Just what I wanted to establish. Now for the next test," I said. "Mark me, Long; do you see those bits of paper along the fence? Go and look at the ground, where they lie, and you will see the faint impression of a wheel. Just before the gate where the vehicle stood for a moment, the print is deeper, and more easily noticed. I said that the gun was fired across the buggy; you have convinced yourself that aim could be taken from only one position, at this distance. The man must stand where those bits of paper are scattered. Now, look;" I bent down and gathered up the fragments of paper; "look close. Here is a fine, free imprint from the heel of a heavy boot. As there is but one, and that so marked, it is reasonable to suppose that the assassin rested one foot upon the buggy wheel, thus throwing his weight upon this heel."
Long bent to examine the print and then lifted his head to ejaculate:
"It is wonderful!"
"It is simplicity itself," I replied; "the a, b, c of the detective's alphabet. I said there were two horses; look, here is where one of them scraped the fence with his teeth, and here the other has snatched a mouthful of leaves from the doctor's young shade tree. Here, too, are some faint, imperfect hoof-prints, but they are enough to tell us, from their position, that there were two horses, and from their size, that the animals were pretty small."
Long examined the different marks with eager attention, and then stood gazing fixedly at me, while I gathered up my bits of paper.
"I shall not try to preserve these as evidence in the case," I said. "I think we shall do very well without them. They were marked for your benefit, solely. Are you convinced?"