CHAPTER VI

      SHERLOCK HOLMES GIVES A DEMONSTRATION

      “Now, Watson,” said Holmes, rubbing his hands, “we have half an hour to ourselves. Let us make good use of it. My case is, as I have told you, almost complete; but we must not err on the side of over-confidence. Simple as the case seems now, there may be something deeper underlying it.”

      “Simple!” I ejaculated.

      “Surely,” said he, with something of the air of a clinical professor expounding to his class. “Just sit in the corner there, that your footprints may not complicate matters. Now to work! In the first place, how did these folk come, and how did they go? The door has not been opened since last night. How of the window?” He carried the lamp across to it, muttering his observations aloud the while, but addressing them to himself rather than to me. “Window is snibbed on the inner side. Framework is solid. No hinges at the side. Let us open it. No water-pipe near. Roof quite out of reach. Yet a man has mounted by the window. It rained a little last night. Here is the print of a foot in mould upon the sill. And here is a circular muddy mark, and here again upon the floor, and here again by the table. See here, Watson! This is really a very pretty demonstration.”

      I looked at the round, well-defined muddy discs.

      “This is not a footmark,” said I.

      “It is something much more valuable to us. It is the impression of a wooden stump. You see here on the sill is the boot-mark, a heavy boot with the broad metal heel, and beside it is the mark of the timber-toe.”

      “It is the wooden-legged man.”

      “Quite so. But there has been some one else—a very able and efficient ally. Could you scale that wall, doctor?”

      I looked out of the open window. The moon still shone brightly on that angle of the house. We were a good sixty feet from the round, and, look where I would, I could see no foothold, nor as much as a crevice in the brickwork.

      “It is absolutely impossible,” I answered.

      “Without aid it is so. But suppose you had a friend up here who lowered you this good stout rope which I see in the corner, securing one end of it to this great hook in the wall. Then, I think, if you were an active man, you might swarm up, wooden leg and all. You would depart, of course, in the same fashion, and your ally would draw up the rope, untie it from the hook, shut the window, snib it on the inside, and get away in the way that he originally came. As a minor point it may be noted,” he continued, fingering the rope, “that our wooden-legged friend, though a fair climber, was not a professional sailor. His hands were far from horny. My lens discloses more than one blood-mark, especially towards the end of the rope, from which I gather that he slipped down with such velocity that he took the skin off his hands.”

      “This is all very well,” said I, “but the thing becomes more unintelligible than ever. How about this mysterious ally? How came he into the room?”

      “Yes, the ally!” repeated Holmes, pensively. “There are features of interest about this ally. He lifts the case from the regions of the commonplace. I fancy that this ally breaks fresh ground in the annals of crime in this country—though parallel cases suggest themselves from India, and, if my memory serves me, from Senegambia.”

      “How came he, then?” I reiterated. “The door is locked, the window is inaccessible. Was it through the chimney?”

      The grate is much too small,” he answered. “I had already considered that possibility.”

      “How then?” I persisted.

      “You will not apply my precept,” he said, shaking his head. “How often have I said to you that when you have eliminated the impossible whatever remains, however improbable, must be the truth? We know that he did not come through the door, the window, or the chimney. We also know that he could not have been concealed in the room, as there is no concealment possible. Whence, then, did he come?”

      “He came through the hole in the roof,” I cried.

      “Of course he did. He must have done so. If you will have the kindness to hold the lamp for me, we shall now extend our researches to the room above—the secret room in which the treasure was found.”

      He mounted the steps, and, seizing a rafter with either hand, he swung himself up into the garret. Then, lying on his face, he reached down for the lamp and held it while I followed him.

      The chamber in which we found ourselves was about ten feet one way and six the other. The floor was formed by the rafters, with thin lath and plaster between, so that in walking one had to step from beam to beam. The roof ran up to an apex, and was evidently the inner shell of the true roof of the house. There was no furniture of any sort, and the accumulated dust of years lay thick upon the floor.

      “Here you are, you see,” said Sherlock Holmes, putting his hand against the sloping wall. “This is a trapdoor which leads out on to the roof. I can press it back, and here is the roof itself, sloping at a gentle angle. This, then, is the way by which Number One entered. Let us see if we can find some other traces of his individuality?”

      He held down the lamp to the floor, and as he did so I saw for the second time that night a startled, surprised look come over his face. For myself, as I followed his gaze my skin was cold under my clothes. The floor was covered thickly with the prints of a naked foot—clear, well defined, perfectly formed, but scarce half the size of those of an ordinary man.

      “Holmes,” I said, in a whisper, “a child has done this horrid thing.”

      He had recovered his self-possession in an instant.

      “I was staggered for the moment,” he said, “but the thing is quite natural. My memory failed me, or I should have been able to foretell it. There is nothing more to be learned here. Let us go down.”

      “What is your theory, then, as to those footmarks?” I asked, eagerly, when we had regained the lower room once more.

      “My dear Watson, try a little analysis yourself,” said he, with a touch of impatience. “You know my methods. Apply them, and it will be instructive to compare results.”

      “I cannot conceive anything which will cover the facts,” I answered.

      “It will be clear enough to you soon,” he said, in an offhand way. “I think that there is nothing else of importance here, but I will look.”

      He whipped out his lens and a tape measure, and hurried about the room on his knees, measuring, comparing, examining, with his long, thin nose only a few inches from the planks, and his beady eyes gleaming and deep-set like those of a bird. So swift, silent, and furtive were his movements, like those of a trained bloodhound picking out a scent, that I