Chapter XVI. Thorndyke Plays His Card

As Thorndyke took his place in the box I looked at him with a sense of unreasonable surprise, feeling that I had never before fully realised what manner of man my friend was as to his externals. I had often noted the quiet strength of his face, its infinite intelligence, its attractiveness and magnetism; but I had never before appreciated what now impressed me most: that Thorndyke was actually the handsomest man I had ever seen. He was dressed simply, his appearance unaided by the flowing gown or awe-inspiring wig, and yet his presence dominated the court. Even the judge, despite his scarlet robe and trappings of office, looked commonplace by comparison, while the jurymen, who turned to look at him, seemed like beings of an inferior order. It was not alone the distinction of the tall figure, erect and dignified, nor the power and massive composure of his face, but the actual symmetry and comeliness of the face itself that now arrested my attention; a comeliness that made it akin rather to some classic mask, wrought in the ivory-toned marble of Pentelicus, than to the eager faces that move around us in the hurry and bustle of a life at once strenuous and trivial.

"You are attached to the medical school at St. Margaret's Hospital, I believe, Dr. Thorndyke?" said Anstey.

"Yes. I am the lecturer on Medical Jurisprudence and Toxicology."

"Have you had much experience of medico-legal inquiries?"

"A great deal. I am engaged exclusively in medico-legal work."

"You heard the evidence relating to the two drops of blood found in the safe?"

"I did."

"What is your opinion as to the condition of that blood?"

"I should say there is no doubt that it had been artificially treated--probably by defibrination."

"Can you suggest any explanation of the condition of that blood?"

"I can."

"Is your explanation connected with any peculiarities in the thumb-print on the paper that was found in the safe?"

"It is."

"Have you given any attention to the subject of finger-prints?"

"Yes. A great deal of attention."

"Be good enough to examine that paper" (here the usher handed to Thorndyke the memorandum slip). "Have you seen it before?"

"Yes. I saw it at Scotland Yard."

"Did you examine it thoroughly?"

"Very thoroughly. The police officials gave me every facility and, with their permission, I took several photographs of it."

"There is a mark on that paper resembling the print of a human thumb?"

"There is."

"You have heard two expert witnesses swear that that mark was made by the left thumb of the prisoner, Reuben Hornby?"

"I have."

"Do you agree to that statement?"

"I do not."

"In your opinion, was the mark upon that paper made by the thumb of the prisoner?"

"No. I am convinced that it was not made by the thumb of Reuben Hornby."

"Do you think that it was made by the thumb of some other person?"

"No. I am of opinion that it was not made by a human thumb at all."

At this statement the judge paused for a moment, pen in hand, and stared at Thorndyke with his mouth slightly open, while the two experts looked at one another with raised eyebrows.

"By what means do you consider that the mark was produced?"

"By means of a stamp, either of indiarubber or, more probably, of chromicized gelatine."

Here Polton, who had been, by degrees, rising to an erect posture, smote his thigh a resounding thwack and chuckled aloud, a proceeding that caused all eyes, including those of the judge, to be turned on him.

"If that noise is repeated," said the judge, with a stony stare at the horrified offender--who had shrunk into the very smallest space that I have ever seen a human being occupy--"I shall cause the person who made it to be removed from the court."

"I understand, then," pursued Anstey, "that you consider the thumb-print, which has been sworn to as the prisoner's, to be a forgery?"

"Yes. It is a forgery."

"But is it possible to forge a thumb-print or a finger-print?"

"It is not only possible, but quite easy to do."

"As easy as to forge a signature, for instance?" "Much more so, and infinitely more secure. A signature, being written with a pen, requires that the forgery should also be written with a pen, a process demanding very special skill and, after all, never resulting in an absolute facsimile. But a finger-print is a stamped impression--the finger-tip being the stamp; and it is only necessary to obtain a stamp identical in character with the finger-tip, in order to produce an impression which is an absolute facsimile, in every respect, of the original, and totally indistinguishable from it."

"Would there be no means at all of detecting the difference between a forged finger-print and the genuine original?"

"None whatever; for the reason that there would be no difference to detect."

"But you have stated, quite positively, that the thumb-print on this paper is a forgery. Now, if the forged print is indistinguishable from the original, how are you able to be certain that this particular print is a forgery?"

"I was speaking of what is possible with due care, but, obviously, a forger might, through inadvertence, fail to produce an absolute facsimile and then detection would be possible. That is what has happened in the present case. The forged print is not an absolute facsimile of the true print. There is a slight discrepancy. But, in addition to this, the paper bears intrinsic evidence that the thumb-print on it is a forgery." "We will consider that evidence presently, Dr. Thorndyke. To return to the possibility of forging a finger-print, can you explain to us, without being too technical, by what methods it would be possible to produce such a stamp as you have referred to?"

"There are two principal methods that suggest themselves to me. The first, which is rather crude though easy to carry out, consists in taking an actual cast of the end of the finger. A mould would be made by pressing the finger into some plastic material, such as fine modelling clay or hot sealing wax, and then, by pouring a warm solution of gelatine into the mould, and allowing it to cool and solidify, a cast would be produced which would yield very perfect finger-prints. But this method would, as a rule, be useless for the purpose of the forger, as it could not, ordinarily, be carried out without the knowledge of the victim; though in the case of dead bodies and persons asleep or unconscious or under an anaesthetic, it could be practised with success, and would offer the advantage of requiring practically no technical skill or knowledge and no special appliances. The second method, which is much more efficient, and is the one, I have no doubt, that has been used in the present instance, requires more knowledge and skill.

"In the first place it is necessary to obtain possession of, or access to, a genuine finger-print. Of this finger-print a photograph is taken, or rather, a photographic negative, which for this purpose requires to be taken on a reversed plate, and the negative is put into a special printing frame, with a plate of gelatine which has been treated with potassium bichromate, and the frame is exposed to light.

"Now gelatine treated in this way--chromicized gelatine, as it is called--has a very peculiar property. Ordinary gelatine, as is well known, is easily dissolved in hot water, and chromicized gelatine is also soluble in hot water as long as it is not exposed to light; but on being exposed to light, it undergoes a change and is no longer capable of being dissolved in hot water. Now the plate of chromicized gelatine under the negative is protected from the light by the opaque parts of the negative, whereas the light passes freely through the transparent parts; but the transparent parts of the negative correspond to the black marks on the finger-print, and these correspond to the ridges on the finger. Hence it follows that the gelatine plate is acted upon by light only on the parts corresponding to the ridges; and in these parts the gelatine is rendered insoluble, while all the rest of the gelatine is soluble. The gelatine plate, which is cemented to a thin plate of metal for support, is now carefully washed with hot water, by which the soluble part of the gelatine is dissolved away leaving the insoluble part (corresponding to the ridges) standing up from the surface. Thus there is produced a facsimile in relief of the finger-print having actual ridges and furrows identical in character with the ridges and furrows of the finger-tip. If an inked roller is passed over this relief, or if the relief is pressed lightly on an inked slab, and then pressed on a sheet of paper, a finger-print will be produced which will be absolutely identical with the original, even to the little white spots which mark the orifices of the sweat glands. It will be impossible to discover any difference between the real finger-print and the counterfeit because, in fact, no difference exists."

"But surely the process you have described is a very difficult and intricate one?"

"Not at all; it is very little more difficult than ordinary carbon printing, which is practised successfully by numbers of amateurs. Moreover, such a relief as I have described--which is practically nothing more than an ordinary process block--could be produced by any photo-engraver. The process that I have described is, in all essentials, that which is used in the reproduction of pen-and-ink drawings, and any of the hundreds of workmen who are employed in that industry could make a relief-block of a finger-print, with which an undetectable forgery could be executed."

"You have asserted that the counterfeit finger-print could not be distinguished from the original. Are you prepared to furnish proof that this is the case?"

"Yes. I am prepared to execute a counterfeit of the prisoner's thumb-print in the presence of the Court."

"And do you say that such a counterfeit would be indistinguishable from the original, even by the experts?"

"I do."

Anstey turned towards the judge. "Would your lordship give your permission for a demonstration such as the witness proposes?"

"Certainly," replied the judge. "The evidence is highly material. How do you propose that the comparison should be made?" he added, addressing Thorndyke.

"I have brought, for the purpose, my lord," answered Thorndyke, "some sheets of paper, each of which is ruled into twenty numbered squares. I propose to make on ten of the squares counterfeits of the prisoner's thumb-mark, and to fill the remaining ten with real thumb-marks. I propose that the experts should then examine the paper and tell the Court which are the real thumb-prints and which are the false."

"That seems a fair and efficient test," said his lordship. "Have you any objection to offer, Sir Hector?"

Sir Hector Trumpler hastily consulted with the two experts, who were sitting in the attorney's bench, and then replied, without much enthusiasm--

"We have no objection to offer, my lord."

"Then, in that case, I shall direct the expert witnesses to withdraw from the court while the prints are being made."

In obedience to the judge's order, Mr. Singleton and his colleague rose and left the court with evident reluctance, while Thorndyke took from a small portfolio three sheets of paper which he handed up to the judge.

"If your lordship," said he, "will make marks in ten of the squares on two of these sheets, one can be given to the jury and one retained by your lordship to check the third sheet when the prints are made on it."

"That is an excellent plan," said the judge; "and, as the information is for myself and the jury, it would be better if you came up and performed the actual stamping on my table in the presence of the foreman of the jury and the counsel for the prosecution and defence."

In accordance with the judge's direction Thorndyke stepped up on the dais, and Anstey, as he rose to follow, leaned over towards me.

"You and Polton had better go up too," said he: "Thorndyke will want your assistance, and you may as well see the fun. I will explain to his lordship."

He ascended the stairs leading to the dais and addressed a few words to the judge, who glanced in our direction and nodded, whereupon we both gleefully followed our counsel, Polton carrying the box and beaming with delight.

The judge's table was provided with a shallow drawer which pulled out at the side and which accommodated the box comfortably, leaving the small table-top free for the papers. When the lid of the box was raised, there were displayed a copper inking-slab, a small roller and the twenty-four "pawns" which had so puzzled Polton, and on which he now gazed with a twinkle of amusement and triumph.

"Are those all stamps?" inquired the judge, glancing curiously at the array of turned-wood handles.

"They are all stamps, my lord," replied Thorndyke, "and each is taken from a different impression of the prisoner's thumb."

"But why so many?" asked the judge.

"I have multiplied them," answered Thorndyke, as he squeezed out a drop of finger-print ink on to the slab and proceeded to roll it out into a thin film, "to avoid the tell-tale uniformity of a single stamp. And I may say," he added, "that it is highly important that the experts should not be informed that more than one stamp has been used."

"Yes, I see that," said the judge. "You understand that, Sir Hector," he added, addressing the counsel, who bowed stiffly, clearly regarding the entire proceeding with extreme disfavour.

Thorndyke now inked one of the stamps and handed it to the judge, who examined it curiously and then pressed it on a piece of waste paper, on which there immediately appeared a very distinct impression of a human thumb. "Marvellous!" he exclaimed. "Most ingenious! Too ingenious!" He chuckled softly and added, as he handed the stamp and the paper to the foreman of the jury: "It is well, Dr. Thorndyke, that you are on the side of law and order, for I am afraid that, if you were on the other side, you would be one too many for the police. Now, if you are ready, we will proceed. Will you, please, stamp an impression in square number three."

Thorndyke drew a stamp from its compartment, inked it on the slab, and pressed it neatly on the square indicated, leaving there a sharp, clear thumb-print.

The process was repeated on nine other squares, a different stamp being used for each impression. The judge then marked the ten corresponding squares of the other two sheets of paper, and having checked them, directed the foreman to exhibit the sheet bearing the false thumb-prints to the jury, together with the marked sheet which they were to retain, to enable them to check the statements of the expert witnesses. When this was done, the prisoner was brought from the dock and stood beside the table. The judge looked with a curious and not unkindly interest at the handsome, manly fellow who stood charged with a crime so sordid and out of character with his appearance, and I felt, as I noted the look, that Reuben would, at least, be tried fairly on the evidence, without prejudice or even with some prepossession in his favour.

With the remaining part of the operation Thorndyke proceeded carefully and deliberately. The inking-slab was rolled afresh for each impression, and, after each, the thumb was cleansed with petrol and thoroughly dried; and when the process was completed and the prisoner led back to the dock, the twenty squares on the paper were occupied by twenty thumb-prints, which, to my eye, at any rate, were identical in character.

The judge sat for near upon a minute poring over this singular document with an expression half-way between a frown and a smile. At length, when we had all returned to our places, he directed the usher to bring in the witnesses.

I was amused to observe the change that had come over the experts in the short interval. The confident smile, the triumphant air of laying down a trump card, had vanished, and the expression of both was one of anxiety, not unmixed with apprehension. As Mr. Singleton advanced hesitatingly to the table, I recalled the words that he had uttered in his room at Scotland Yard; evidently his scheme of the game that was to end in an easy checkmate, had not included the move that had just been made.

"Mr. Singleton," said the judge, "here is a paper on which there are twenty thumb-prints. Ten of them are genuine prints of the prisoner's left thumb and ten are forgeries. Please examine them and note down in writing which are the true prints and which are the forgeries. When you have made your notes the paper will be handed to Mr. Nash."

"Is there any objection to my using the photograph that I have with me for comparison, my lord?" asked Mr. Singleton.

"I think not," replied the judge. "What do you say, Mr. Anstey?"

"No objection whatever, my lord," answered Anstey.

Mr. Singleton accordingly drew from his pocket an enlarged photograph of the thumb-print and a magnifying glass, with the aid of which he explored the bewildering array of prints on the paper before him; and as he proceeded I remarked with satisfaction that his expression became more and more dubious and worried. From time to time he made an entry on a memorandum slip beside him, and, as the entries accumulated, his frown grew deeper and his aspect more puzzled and gloomy.

At length he sat up, and taking the memorandum slip in his hand, addressed the judge.

"I have finished my examination, my lord."

"Very well. Mr. Nash, will you kindly examine the paper and write down the results of your examination?"

"Oh! I wish they would make haste," whispered Juliet. "Do you think they will be able to tell the real from the false thumb-prints?"

"I can't say," I replied; "but we shall soon know. They looked all alike to me."

Mr. Nash made his examination with exasperating deliberateness, and preserved throughout an air of stolid attention; but at length he, too, completed his notes and handed the paper back to the usher.

"Now, Mr. Singleton," said the judge, "let us hear your conclusions. You have been sworn."

Mr. Singleton stepped into the witness-box, and, laying his notes on the ledge, faced the judge.

"Have you examined the paper that was handed to you?" asked Sir Hector Trumpler.

"I have."

"What did you see on the paper?"

"I saw twenty thumb-prints, of which some were evident forgeries, some were evidently genuine, and some were doubtful."

"Taking the thumb-prints seriatim, what have you noted about them?"

Mr. Singleton examined his notes and replied--"The thumb-print on square one is evidently a forgery, as is also number two, though it is a passable imitation. Three and four are genuine; five is an obvious forgery. Six is a genuine thumb-print; seven is a forgery, though a good one; eight is genuine; nine is, I think, a forgery, though it is a remarkably good imitation. Ten and eleven are genuine thumb-marks; twelve and thirteen are forgeries; but as to fourteen I am very doubtful, though I am inclined to regard it as a forgery. Fifteen is genuine, and I think sixteen is also; but I will not swear to it. Seventeen is certainly genuine Eighteen and nineteen I am rather doubtful about, but I am disposed to consider them both forgeries. Twenty is certainly a genuine thumb-print."

As Mr. Singleton's evidence proceeded, a look of surprise began to make its appearance on the judge's face, while the jury glanced from the witness to the notes before them and from their notes to one another in undisguised astonishment.

As to Sir Hector Trumpler, that luminary of British jurisprudence was evidently completely fogged; for, as statement followed statement, he pursed up his lips and his broad, red face became overshadowed by an expression of utter bewilderment.

For a few seconds he stared blankly at his witness and then dropped on to his seat with a thump that shook the court.

"You have no doubt," said Anstey, "as to the correctness of your conclusions? For instance, you are quite sure that the prints one and two are forgeries?"

"I have no doubt."

"You swear that those two prints are forgeries?"

Mr. Singleton hesitated for a moment. He had been watching the judge and the jury and had apparently misinterpreted their surprise, assuming it to be due to his own remarkable powers of discrimination; and his confidence had revived accordingly.

"Yes," he answered; "I swear that they are forgeries."

Anstey sat down, and Mr. Singleton, having passed his notes up to the judge, retired from the box, giving place to his colleague.

Mr. Nash, who had listened with manifest satisfaction to the evidence, stepped into the box with all his original confidence restored. His selection of the true and the false thumb-prints was practically identical with that of Mr. Singleton, and his knowledge of this fact led him to state his conclusions with an air that was authoritative and even dogmatic.

"I am quite satisfied of the correctness of my statements," he said, in reply to Anstey's question, "and I am prepared to swear, and do swear, that those thumb-prints which I have stated to be forgeries, are forgeries, and that their detection presents no difficulty to an observer who has an expert acquaintance with finger-prints."

"There is one question that I should like to ask," said the judge, when the expert had left the box and Thorndyke had re-entered it to continue his evidence. "The conclusions of the expert witnesses--manifestly bona fide conclusions, arrived at by individual judgement, without collusion or comparison of results--are practically identical. They are virtually in complete agreement. Now, the strange thing is this: their conclusions are wrong in every instance" (here I nearly laughed aloud, for, as I glanced at the two experts, the expression of smug satisfaction on their countenances changed with lightning rapidity to a ludicrous spasm of consternation); "not sometimes wrong and sometimes right, as would have been the case if they had made mere guesses, but wrong every time. When they are quite certain, they are quite wrong; and when they are doubtful, they incline to the wrong conclusion. This is a very strange coincidence, Dr. Thorndyke. Can you explain it?"

Thorndyke's face, which throughout the proceedings had been as expressionless as that of a wooden figurehead, now relaxed into a dry smile.

"I think I can, my lord," he replied. "The object of a forger in executing a forgery is to produce deception on those who shall examine the forgery."

"Ah!" said the judge; and his face relaxed into a dry smile, while the jury broke out into unconcealed grins.

"It was evident to me," continued Thorndyke, "that the experts would be unable to distinguish the real from the forged thumb-prints, and, that being so, that they would look for some collateral evidence to guide them. I, therefore, supplied that collateral evidence. Now, if ten prints are taken, without special precautions, from a single finger, it will probably happen that no two of them are exactly alike; for the finger being a rounded object of which only a small part touches the paper, the impressions produced will show little variations according to the part of the finger by which 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 finger-tip, 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 finger-prints, 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 attracted by Walter Hornby. An expression of terror and wild despair had settled on his face, which was ghastly in its pallor and bedewed with sweat. He looked furtively at Thorndyke and, as I noted the murderous hate in his eyes, I recalled our midnight adventure in John Street and the mysterious cigar.

Suddenly he rose to his feet, wiping his brow and steadying himself against the bench with a shaking hand; then he walked quietly to the door and went out. Apparently, I was not the only onlooker who had been interested in his doings, for, as the door swung to after him, Superintendent Miller rose from his seat and went out by the other door.

"Are you cross-examining this witness?" the judge inquired, glancing at Sir Hector Trumpler.

"No, my lord," was the reply.

"Are you calling any more witnesses, Mr. Anstey?"

"Only one, my lord," replied Anstey--"the prisoner, whom I shall put in the witness-box, as a matter of form, in order that he may make a statement on oath."

Reuben was accordingly conducted from the dock to the witness-box, and, having been sworn, made a solemn declaration of his innocence. A brief cross-examination followed, in which nothing was elicited, but that Reuben had spent the evening at his club and gone home to his rooms about half-past eleven and had let himself in with his latchkey. Sir Hector at length sat down; the prisoner was led back to the dock, and the Court settled itself to listen to the speeches of the counsel.

"My lord and gentlemen of the jury," Anstey commenced in his clear, mellow tones, "I do not propose to occupy your time with a long speech. The evidence that has been laid before you is at once so intelligible, so lucid, and so conclusive, that you will, no doubt, arrive at your verdict uninfluenced by any display of rhetoric either on my part or on the part of the learned counsel for the prosecution.

"Nevertheless, it is desirable to disentangle from the mass of evidence those facts which are really vital and crucial.

"Now the one fact which stands out and dominates the whole case is this: The prisoner's connection with this case rests solely upon the police theory of the infallibility of finger-prints. Apart from the evidence of the thumb-print there is not, and there never was, the faintest breath of suspicion against him. You have heard him described as a man of unsullied honour, as a man whose character is above reproach; a man who is trusted implicitly by those who have had dealings with him. And this character was not given by a casual stranger, but by one who has known him from childhood. His record is an unbroken record of honourable conduct; his life has been that of a clean-living, straightforward gentleman. And now he stands before you charged with a miserable, paltry theft; charged with having robbed that generous friend, the brother of his own father, the guardian of his childhood and the benefactor who has planned and striven for his well-being; charged, in short, gentlemen, with a crime which every circumstance connected with him and every trait of his known character renders utterly inconceivable. Now upon what grounds has this gentleman of irreproachable character been charged with this mean and sordid crime? Baldly stated, the grounds of the accusation are these: A certain learned and eminent man of science has made a statement, which the police have not merely accepted but have, in practice, extended beyond its original meaning. That statement is as follows: 'A complete, or nearly complete, accordance between two prints of a single finger ... affords evidence requiring no corroboration, that the persons from whom they were made are the same.'

"That statement, gentlemen, is in the highest degree misleading, and ought not to have been made without due warning and qualification. So far is it from being true, in practice, that its exact contrary is the fact; the evidence of a finger-print, in the absence of corroboration, is absolutely worthless. Of all forms of forgery, the forgery of a finger-print is the easiest and most secure, as you have seen in this court to-day. Consider the character of the high-class forger--his skill, his ingenuity, his resource. Think of the forged banknotes, of which not only the engraving, the design and the signature, but even the very paper with its private watermarks, is imitated with a perfection that is at once the admiration and the despair of those who have to distinguish the true from the false; think of the forged cheque, in which actual perforations are filled up, of which portions are cut out bodily and replaced by indistinguishable patches; think of these, and then of a finger-print, of which any photo-engraver's apprentice can make you a forgery that the greatest experts cannot distinguish from the original, which any capable amateur can imitate beyond detection after a month's practice; and then ask yourselves if this is the kind of evidence on which, without any support or corroboration, a gentleman of honour and position should be dragged before a criminal court and charged with having committed a crime of the basest and most sordid type. "But I must not detain you with unnecessary appeals. I will remind you briefly of the salient facts. The case for the prosecution rests upon the assertion that the thumb-print found in the safe was made by the thumb of the prisoner. If that thumb-print was not made by the prisoner, there is not only no case against him but no suspicion of any kind.

"Now, was that thumb-print made by the prisoner's thumb? You have had conclusive evidence that it was not. That thumb-print differed in the size, or scale, of the pattern from a genuine thumb-print of the prisoner's. The difference was small, but it was fatal to the police theory; the two prints were not identical.

"But, if not the prisoner's thumb-print, what was it? The resemblance of the pattern was too exact for it to be the thumb-print of another person, for it reproduced not only the pattern of the ridges on the prisoner's thumb, but also the scar of an old wound. The answer that I propose to this question is, that it was an intentional imitation of the prisoner's thumb-print, made with the purpose of fixing suspicion on the prisoner, and so ensuring the safety of the actual criminal. Are there any facts which support this theory? Yes, there are several facts which support it very strongly.

"First, there are the facts that I have just mentioned. The red thumb-print disagreed with the genuine print in its scale or dimensions. It was not the prisoner's thumb-print; but neither was it that of any other person. The only alternative is that it was a forgery.

"In the second place, that print was evidently made with the aid of certain appliances and materials, and one of those materials, namely defibrinated blood, was found in the safe.

"In the third place, there is the coincidence that the print was one which it was possible to forge. The prisoner has ten digits--eight fingers and two thumbs. But there were in existence actual prints of the two thumbs, whereas no prints of the fingers were in existence; hence it would have been impossible to forge a print of any of the fingers. So it happens that the red thumb-print resembled one of the two prints of which forgery was possible.

"In the fourth place, the red thumb-print reproduces an accidental peculiarity of the 'Thumbograph' print. Now, if the red thumb-print is a forgery, it must have been made from the 'Thumbograph' print, since there exists no other print from which it could have been made. Hence we have the striking fact that the red thumb-print is an exact replica--including accidental peculiarities--of the only print from which a forgery could have been made. The accidental S-shaped mark in the 'Thumbograph' print is accounted for by the condition of the paper; the occurrence of this mark in the red thumb-print is not accounted for by any peculiarity of the paper, and can be accounted for in no way, excepting by assuming the one to be a copy of the other. The conclusion is thus inevitable that the red thumb-print is a photo-mechanical reproduction of the 'Thumbograph' print.

"But there is yet another point. If the red thumb-print is a forgery reproduced from the 'Thumbograph' print, the forger must at some time have had access to the 'Thumbograph.' Now, you have heard Mrs. Hornby's remarkable story of the mysterious disappearance of the 'Thumbograph' and its still more mysterious reappearance. That story can have left no doubt in your minds that some person had surreptitiously removed the 'Thumbograph' and, after an unknown interval, secretly replaced it. Thus the theory of forgery receives confirmation at every point, and is in agreement with every known fact; whereas the theory that the red thumb-print was a genuine thumb-print, is based upon a gratuitous assumption, and has not had a single fact advanced in its support.

"Accordingly, gentlemen, I assert that the prisoner's innocence has been proved in the most complete and convincing manner, and I ask you for a verdict in accordance with that proof."

As Anstey resumed his seat, a low rumble of applause was heard from the gallery. It subsided instantly on a gesture of disapproval from the judge, and a silence fell upon the court, in which the clock, with cynical indifference, continued to record in its brusque monotone the passage of the fleeting seconds.

"He is saved, Dr. Jervis! Oh! surely he is saved!" Juliet exclaimed in an agitated whisper. "They must see that he is innocent now."

"Have patience a little longer," I answered. "It will soon be over now."

Sir Hector Trumpler was already on his feet and, after bestowing on the jury a stern hypnotic stare, he plunged into his reply with a really admirable air of conviction and sincerity. "My lord and gentlemen of the jury: The case which is now before this Court is one, as I have already remarked, in which human nature is presented in a highly unfavourable light. But I need not insist upon this aspect of the case, which will already, no doubt, have impressed you sufficiently. It is necessary merely for me, as my learned friend has aptly expressed it, to disentangle the actual facts of the case from the web of casuistry that has been woven around them.

"Those facts are of extreme simplicity. A safe has been opened and property of great value abstracted from it. It has been opened by means of false keys. Now there are two men who have, from time to time, had possession of the true keys, and thus had the opportunity of making copies of them. When the safe is opened by its rightful owner, the property is gone, and there is found the print of the thumb of one of these two men. That thumb-print was not there when the safe was closed. The man whose thumb-print is found is a left-handed man; the print is the print of a left thumb. It would seem, gentlemen, as if the conclusion were so obvious that no sane person could be found to contest it; and I submit that the conclusion which any sane person would arrive at--the only possible conclusion--is, that the person whose thumb-print was found in the safe is the person who stole the property from the safe. But the thumb-print was, admittedly, that of the prisoner at the bar, and therefore the prisoner at the bar is the person who stole the diamonds from the safe.

"It is true that certain fantastic attempts have been made to explain away these obvious facts. Certain far-fetched scientific theories have been propounded and an exhibition of legerdemain has taken place which, I venture to think, would have been more appropriate to some place of public entertainment than to a court of justice. That exhibition has, no doubt, afforded you considerable amusement. It has furnished a pleasing relaxation from the serious business of the court. It has even been instructive, as showing to what extent it is possible for plain facts to be perverted by misdirected ingenuity. But unless you are prepared to consider this crime as an elaborate hoax--as a practical joke carried out by a facetious criminal of extraordinary knowledge, skill and general attainments--you must, after all, come to the only conclusion that the facts justify: that the safe was opened and the property abstracted by the prisoner. Accordingly, gentlemen, I ask you, having regard to your important position as the guardians of the well-being and security of your fellow-citizens, to give your verdict in accordance with the evidence, as you have solemnly sworn to do; which verdict, I submit, can be no other than that the prisoner is guilty of the crime with which he is charged."

Sir Hector sat down, and the jury, who had listened to his speech with solid attention, gazed expectantly at the judge, as though they should say: "Now, which of these two are we to believe?"

The judge turned over his notes with an air of quiet composure, writing down a word here and there as he compared the various points in the evidence. Then he turned to the jury with a manner at once persuasive and confidential--

"It is not necessary, gentlemen," he commenced, "for me to occupy your time with an exhaustive analysis of the evidence. That evidence you yourselves have heard, and it has been given, for the most part, with admirable clearness. Moreover, the learned counsel for the defence has collated and compared that evidence so lucidly, and, I may say, so impartially, that a detailed repetition on my part would be superfluous. I shall therefore confine myself to a few comments which may help you in the consideration of your verdict.

"I need hardly point out to you that the reference made by the learned counsel for the prosecution to far-fetched scientific theories is somewhat misleading. The only evidence of a theoretical character was that of the finger-print experts. The evidence of Dr. Rowe and of Dr. Thorndyke dealt exclusively with matters of fact. Such inferences as were drawn by them were accompanied by statements of the facts which yielded such inferences.

"Now, an examination of the evidence which you have heard shows, as the learned counsel for the defence has justly observed, that the entire case resolves itself into a single question, which is this: 'Was the thumb-print that was found in Mr. Hornby's safe made by the thumb of the prisoner, or was it not?' If that thumb-print was made by the prisoner's thumb, then the prisoner must, at least, have been present when the safe was unlawfully opened. If that thumb-print was not made by the prisoner's thumb, there is nothing to connect him with the crime. The question is one of fact upon which it will be your duty to decide; and I must remind you, gentlemen, that you are the sole judges of the facts of the case, and that you are to consider any remarks of mine as merely suggestions which you are to entertain or to disregard according to your judgement.

"Now let us consider this question by the light of the evidence. This thumb-print was either made by the prisoner or it was not. What evidence has been brought forward to show that it was made by the prisoner? Well, there is the evidence of the ridge-pattern. That pattern is identical with the pattern of the prisoner's thumb-print, and even has the impression of a scar which crosses the pattern in a particular manner in the prisoner's thumb-print. There is no need to enter into the elaborate calculations as to the chances of agreement; the practical fact, which is not disputed, is that if this red thumb-print is a genuine thumb-print at all, it was made by the prisoner's thumb. But it is contended that it is not a genuine thumb-print; that it is a mechanical imitation--in fact a forgery.

"The more general question thus becomes narrowed down to the more particular question: 'Is this a genuine thumb-print or is it a forgery?' Let us consider the evidence. First, what evidence is there that it is a genuine thumb-print? There is none. The identity of the pattern is no evidence on this point, because a forgery would also exhibit identity of pattern. The genuineness of the thumb-print was assumed by the prosecution, and no evidence has been offered.

"But now what evidence is there that the red thumb-print is a forgery?

"First, there is the question of size. Two different-sized prints could hardly be made by the same thumb. Then there is the evidence of the use of appliances. Safe-robbers do not ordinarily provide themselves with inking-slabs and rollers with which to make distinct impressions of their own fingers. Then there is the accidental mark on the print which also exists on the only genuine print that could have been used for the purpose of forgery, which is easily explained on the theory of a forgery, but which is otherwise totally incomprehensible. Finally, there is the strange disappearance of the 'Thumbograph' and its strange reappearance. All this is striking and weighty evidence, to which must be added that adduced by Dr. Thorndyke as showing how perfectly it is possible to imitate a finger-print.

"These are the main facts of the case, and it is for you to consider them. If, on careful consideration, you decide that the red thumb-print was actually made by the prisoner's thumb, then it will be your duty to pronounce the prisoner guilty; but if, on weighing the evidence, you decide that the thumb-print is a forgery, then it will be your duty to pronounce the prisoner not guilty. It is now past the usual luncheon hour, and, if you desire it, you can retire to consider your verdict while the Court adjourns."

The jurymen whispered together for a few moments and then the foreman stood up.

"We have agreed on our verdict, my lord," he said.

The prisoner, who had just been led to the back of the dock, was now brought back to the bar. The grey-wigged clerk of the court stood up and addressed the jury.

"Are you all agreed upon your verdict, gentlemen?"

"We are," replied the foreman.

"What do you say, gentlemen? Is the prisoner guilty or not guilty?"

"Not guilty," replied the foreman, raising his voice and glancing at Reuben.

A storm of applause burst from the gallery and was, for the moment, disregarded by the judge. Mrs. Hornby laughed aloud--a strange, unnatural laugh--and then crammed her handkerchief into her mouth, and so sat gazing at Reuben with the tears coursing down her face, while Juliet laid her head upon the desk and sobbed silently.

After a brief space the judge raised an admonitory hand, and, when the commotion had subsided, addressed the prisoner, who stood at the bar, calm and self-possessed, though his face bore a slight flush--

"Reuben Hornby, the jury, after duly weighing the evidence in this case, have found you to be not guilty of the crime with which you were charged. With that verdict I most heartily agree. In view of the evidence which has been given, I consider that no other verdict was possible, and I venture to say that you leave this court with your innocence fully established, and without a stain upon your character. In the distress which you have recently suffered, as well as in your rejoicing at the verdict of the jury, you have the sympathy of the Court, and of everyone present, and that sympathy will not be diminished by the consideration that, with a less capable defence, the result might have been very different.

"I desire to express my admiration at the manner in which that defence was conducted, and I desire especially to observe that not you alone, but the public at large, are deeply indebted to Dr. Thorndyke, who, by his insight, his knowledge and his ingenuity, has probably averted a very serious miscarriage of justice. The Court will now adjourn until half-past two."

The judge rose from his seat and everyone present stood up; and, amidst the clamour of many feet upon the gallery stairs, the door of the dock was thrown open by a smiling police officer and Reuben came down the stairs into the body of the court.