"Hang the will!" exclaimed Stephen. "I want to hear how you propose to lay hands on the villain who murdered poor old uncle Jeffrey—for I suppose he did murder him?"
"I think there is no doubt of it," replied Thorndyke.
"Then," said Marchmont, "we will hear the rest of the argument, if you please."
"Very well," said Thorndyke. "As the evidence stands, we have proved that Jeffrey Blackmore was a prisoner in the house in Kennington Lane and that some one was personating him at New Inn. That some one, we have seen, was, in all probability, John Blackmore. We now have to consider the man Weiss. Who was he? and can we connect him in any way with New Inn?
"We may note in passing that Weiss and the coachman were apparently one and the same person. They were never seen together. When Weiss was present, the coachman was not available even for so urgent a service as the obtaining of an antidote to the poison. Weiss always appeared some time after Jervis's arrival and disappeared some time before his departure, in each case sufficiently long to allow of a change of disguise. But we need not labour the point, as it is not of primary importance.
"To return to Weiss. He was clearly heavily disguised, as we see by his unwillingness to show himself even by the light of a candle. But there is an item of positive evidence on this point which is important from having other bearings. It is furnished by the spectacles worn by Weiss, of which you have heard Jervis's description. These spectacles had very peculiar optical properties. When you looked through them they had the properties of plain glass; when you looked at them they had the appearance of lenses. But only one kind of glass possesses these properties; namely, that which, like an ordinary watch-glass, has curved, parallel surfaces. But for what purpose could a person wear 'watch-glass' spectacles? Clearly, not to assist his vision. The only alternative is disguise.
"The properties of these spectacles introduce a very curious and interesting feature into the case. To the majority of persons, the wearing of spectacles for the purpose of disguise or personation, seems a perfectly simple and easy proceeding. But, to a person of normal eyesight, it is nothing of the kind. For, if he wears spectacles suited for long sight he cannot see distinctly through them at all; while, if he wears concave, or near sight, glasses, the effort to see through them produces such strain and fatigue that his eyes become disabled altogether. On the stage the difficulty is met by using spectacles of plain window-glass, but in real life this would hardly do; the 'property' spectacles would be detected at once and give rise to suspicion.
"The personator is therefore in this dilemma: if he wears actual spectacles, he cannot see through them; if he wears sham spectacles of plain glass, his disguise will probably be detected. There is only one way out of the difficulty, and that not a very satisfactory one; but Mr. Weiss seems to have adopted it in lieu of a better. It is that of using watch-glass spectacles such as I have described.
"Now, what do we learn from these very peculiar glasses? In the first place they confirm our opinion that Weiss was wearing a disguise. But, for use in a room so very dimly lighted, the ordinary stage spectacles would have answered quite well. The second inference is, then, that these spectacles were prepared to be worn under more trying conditions of light—out of doors, for instance. The third inference is that Weiss was a man with normal eyesight; for otherwise he could have worn real spectacles suited to the state of his vision.
"These are inferences by the way, to which we may return. But these glasses furnish a much more important suggestion. On the floor of the bedroom at New Inn I found some fragments of glass which had been trodden on. By joining one or two of them together, we have been able to make out the general character of the object of which they formed parts. My assistant—who was formerly a watch-maker—judged that object to be the thin crystal glass of a lady's watch, and this, I think, was Jervis's opinion. But the small part which remains of the original edge furnishes proof in two respects that this was not a watch-glass. In the first place, on taking a careful tracing of this piece of the edge, I found that its curve was part of an ellipse; but watch-glasses, nowadays, are invariably circular. In the second place, watch-glasses are ground on the edge to a single bevel to snap into the bezel or frame; but the edge of this object was ground to a double bevel, like the edge of a spectacle-glass, which fits into a groove in the frame and is held by the side-bar screw. The inevitable inference was that this was a spectacle-glass. But, if so, it was part of a pair of spectacles identical in properties with those worn by Mr. Weiss.
"The importance of this conclusion emerges when we consider the exceptional character of Mr. Weiss's spectacles. They were not merely peculiar or remarkable; they were probably unique. It is exceedingly likely that there is not in the entire world another similar pair of spectacles. Whence the finding of these fragments of glass in the bedroom establishes a considerable probability that Mr. Weiss was, at some time, in the chambers at New Inn.
"And now let us gather up the threads of this part of the argument. We are inquiring into the identity of the man Weiss. Who was he?
"In the first place, we find him committing a secret crime from which John Blackmore alone will benefit. This suggests the prima-facie probability that he was John Blackmore.
"Then we find that he was a man of normal eyesight who was wearing spectacles for the purpose of disguise. But the tenant of New Inn, whom we have seen to be, almost certainly, John Blackmore—and whom we will, for the present, assume to have been John Blackmore—was a man with normal eyesight who wore spectacles for disguise.
"John Blackmore did not reside at New Inn, but at some place within easy reach of it. But Weiss resided at a place within easy reach of New Inn.
"John Blackmore must have had possession and control of the person of Jeffrey. But Weiss had possession and control of the person of Jeffrey.
"Weiss wore spectacles of a certain peculiar and probably unique character. But portions of such spectacles were found in the chambers at New Inn.
"The overwhelming probability, therefore, is that Weiss and the tenant of New Inn were one and the same person; and that that person was John Blackmore."
"That," said Mr. Winwood, "is a very plausible argument. But, you observe, sir, that it contains an undistributed middle term."
Thorndyke smiled genially. I think he forgave Winwood everything for that remark.
"You are quite right, sir," he said. "It does. And, for that reason, the demonstration is not absolute. But we must not forget, what logicians seem occasionally to overlook: that the 'undistributed middle,' while it interferes with absolute proof, may be quite consistent with a degree of probability that approaches very near to certainty. Both the Bertillon system and the English fingerprint system involve a process of reasoning in which the middle term is undistributed. But the great probabilities are accepted in practice as equivalent to certainties."
Mr. Winwood grunted a grudging assent, and Thorndyke resumed:
"We have now furnished fairly conclusive evidence on three heads: we have proved that the sick man, Graves, was Jeffrey Blackmore; that the tenant of New Inn was John Blackmore; and that the man Weiss was also John Blackmore. We now have to prove that John and Jeffrey were together in the chambers at New Inn on the night of Jeffrey's death.
"We know that two persons, and two persons only, came from Kennington Lane to New Inn. But one of those persons was the tenant of New Inn—that is, John Blackmore. Who was the other? Jeffrey is known by us to have been at Kennington Lane. His body was found on the following morning in the room at New Inn. No third person is known to have come from Kennington Lane; no third person is known СКАЧАТЬ