“Look here, Carmichael,” said Gordon, “this is where you come in. Get out your stethoscope and go down on all-fours and find clues for us.”
“I am afraid that a person entering a room and taking a book away does not commonly leave very much mark on the surroundings. Let’s take a look round, by all means—it’s Sunday, after all, and the housemaid won’t have been dusting. Maids, you will notice, always polish the grates on Sunday but do not dust the rooms; why, I cannot say. Whereabouts did you put the book, Reeves?”
“On that shelf there, the top but one.”
“It was natural for you to put it there, because it’s within your reach. But you’re tall—I wonder if the other gentleman was shorter? I think a chair would be useful here. . . . Thank you. Yes, he was a good deal shorter. He had to stand on tip-toe to reach the book, and balanced himself, as we all do in such circumstances, by resting the four finger-tips of his left hand on the edge of the shelf beneath. In that way, you see, he could get the forefinger of his right hand on the top of the book. I should say he was a man of about Gordon’s height.”
“Unmasked!” cried Gordon, recoiling dramatically. “Send for the Black Maria; I’ll go quiet.”
“I was about to observe, my dear Gordon, that I attach no suspicion to you, because you have unusually long arms for your height. But this man, on the usual calculations, would be about your height, or a little smaller. Now, I wonder if he poked about in the other shelves at all? Most people, when they are looking for a book, take out one or two of the other books in mere inadvertent curiosity. Extraordinary the fascination that books have. I am told that Whitewell, at Oxford, loses twenty pounds’ worth of books a year by theft, as the result of letting people prowl round his shop at their pleasure. Ah! Reeves, your room is an excellent subject for the detective.”
“Why mine, particularly?”
“Because you are a man of such tidy habits.”
“Tidy!” protested Gordon. “Look at those letters on the table.”
“Pernickety would perhaps have been the just word. You are the sort of man who cannot leave a thing lying on the floor, he must pick it up. Consequently, you are the kind of man who always keeps his books on a dead level: some people do, some don’t. Now, if this Shakespeare had been protruding like that yesterday, you would have noticed it and pushed it in.”