LITMIR.BIZ

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the print is made. But a stamp such as I have used has a flat surface like that of a printer’s type, and, like a type, it always prints the same impression. It does not reproduce the fingertip, but a particular print of the finger, and so, if ten prints are made with a single stamp, each print will be a mechanical repetition of the other nine. Thus, on a sheet bearing twenty fingerprints, of which ten were forgeries made with a single stamp, it would be easy to pick out the ten forged prints by the fact that they would all be mechanical repetitions of one another; while the genuine prints could be distinguished by the fact of their presenting trifling variations in the position of the finger.

      “Anticipating this line of reasoning, I was careful to make each print with a different stamp and each stamp was made from a different thumb-print, and I further selected thumb-prints which varied as widely as possible when I made the stamps. Moreover, when I made the real thumb-prints, I was careful to put the thumb down in the same position each time as far as I was able; and so it happened that, on the sheet submitted to the experts, the real thumb-prints were nearly all alike, while the forgeries presented considerable variations. The instances in which the witnesses were quite certain were those in which I succeeded in making the genuine prints repeat one another, and the doubtful cases were those in which I partially failed.”

      “Thank you, that is quite clear,” said the judge, with a smile of deep content, such as is apt to appear on the judicial countenance when an expert witness is knocked off his pedestal. “We may now proceed, Mr. Anstey.”

      “You have told us,” resumed Anstey, “and have submitted proofs, that it is possible to forge a thumb-print so that detection is impossible. You have also stated that the thumb-print on the paper found in Mr. Hornby’s safe is a forgery. Do you mean that it may be a forgery, or that it actually is one?”

      “I mean that it actually is a forgery.”

      “When did you first come to the conclusion that it was a forgery?”

      “When I saw it at Scotland Yard. There are three facts which suggested this conclusion. In the first place the print was obviously produced with liquid blood, and yet it was a beautifully clear and distinct impression. But such an impression could not be produced with liquid blood without the use of a slab and roller, even if great care were used, and still less could it have been produced by an accidental smear.

      “In the second place, on measuring the print with a micrometer, I found that it did not agree in dimensions with a genuine thumb-print of Reuben Hornby. It was appreciably larger. I photographed the print with the micrometer in contact and on comparing this with a genuine thumb-print, also photographed with the same micrometer in contact, I found that the suspected print was larger by the fortieth of an inch, from one given point on the ridge-pattern to another given point. I have here enlargements of the two photographs in which the disagreement in size is clearly shown by the lines of the micrometer. I have also the micrometer itself and a portable microscope, if the Court wishes to verify the photographs.”

      “Thank you,” said the judge, with a bland smile; “we will accept your sworn testimony unless the learned counsel for the prosecution demands verification.”

      He received the photographs which Thorndyke handed up and, having examined them with close attention, passed them on to the jury.

      “The third fact,” resumed Thorndyke, “is of much more im­portance, since it not only proves the print to be a forgery, but also furnishes a very distinct clue to the origin of the forgery, and so to the identity of the forger.” (Here the court became hushed until the silence was so profound that the ticking of the clock seemed a sensible interruption. I glanced at Walter, who sat motionless and rigid at the end of the bench, and perceived that a horrible pallor had spread over his face, while his forehead was covered with beads of perspiration.) “On looking at the print closely, I noticed at one part a minute white mark or space. It was of the shape of a capital S and had evidently been produced by a defect in the paper—a loose fibre which had stuck to the thumb and been detached by it from the paper, leaving a blank space where it had been. But, on examining the paper under a low power of the microscope, I found the surface to be perfect and intact. No loose fibre had been detached from it, for if it had, the broken end or, at least, the groove in which it had lain, would have been visible. The inference seemed to be that the loose fibre had existed, not in the paper which was found in the safe, but in the paper on which the original thumb-mark had been made. Now, as far as I knew, there was only one undoubted thumb-print of Reuben Hornby’s in existence—the one in the ‘Thumbograph.’ At my request, the ‘Thumbograph’ was brought to my chambers by Mrs. Hornby, and, on examining the print of Reuben Hornby’s left thumb, I perceived on it a minute, S-shaped white space occupying a similar position to that in the red thumb-mark; and when I looked at it through a powerful lens, I could clearly see the little groove in the paper in which the fibre had lain and from which it had been lifted by the inked thumb. I subsequently made a systematic comparison of the marks in the two thumb-prints; I found that the dimensions of the mark were proportionally the same in each—that is to say, the mark in the ‘Thumbograph’ print had an extreme length of 26/1000 of an inch and an extreme breadth of 14.5/1000 of an inch, while that in the red thumb-mark was one-fortieth larger in each dimension, having an extreme length of 26.65/1000 of an inch and an extreme breadth of 14.86/1000 of an inch; that the shape was identical, as was shown by superimposing tracings of greatly enlarged photographs of each mark on similar enlargements of the other; and that the mark intersected the ridges of the thumb-print in the same manner and at exactly the same parts in the two prints.”

      “Do you say that—having regard to the facts which you have stated—it is certain that the red thumb-mark is a forgery?”

      “I do; and I also say that it is certain that the forgery was executed by means of the ‘Thumbograph.’”

      “Might not the resemblances be merely a coincidence?”

      “No. By the law of probabilities which Mr. Singleton ex­plained so clearly in his evidence, the adverse chances would run into untold millions. Here are two thumb-prints made in different places and at different times—an interval of many weeks intervening. Each of them bears an accidental mark which is due not to any peculiarity of the thumb, but to a peculiarity of the paper. On the theory of coincidences it is necessary to suppose that each piece of paper had a loose fibre of exactly identical shape and size and that this fibre came, by accident, in contact with the thumb at exactly the same spot. But such a supposition would be more opposed to probabilities even than the supposition that two exact­ly similar thumb-prints should have been made by different persons. And then there is the further fact that the paper found in the safe had no loose fibre to account for the mark.”

      “What is your explanation of the presence of defibrinated blood in the safe?”

      “It was probably used by the forger in making the thumb-print, for which purpose fresh blood would be less suitable by reason of its clotting. He would probably have carried a small quantity in a bottle, together with the pocket slab and roller invented by Mr. Galton. It would thus be possible for him to put a drop on the slab, roll it out into a thin film and take a clean impression with his stamp. It must be remembered that these precautions were quite necessary, since he had to make a recognisable print at the first attempt. A failure and a second trial would have destroyed the accidental appearance, and might have aroused suspicion.”

      “You have made some enlarged photographs of the thumb-prints, have you not?”

      “Yes. I have here two enlarged photographs, one of the ‘Thumb­o­graph’ print and one of the red thumb-print. They both show the white mark very clearly and will assist comparison of the originals, in which the mark is plainly visible through a lens.”

      He handed the two photographs up to the judge, together with the ‘Thumbograph,’ the memorandum slip, and a powerful doublet lens with which to examine them.

      The judge inspected the two original documents with the aid of the lens and compared them with the photographs, nodding approvingly as he made out the points of agreement. Then he passed them on to the jury and made an entry in his notes.

      While this was going on my attention was

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