Our little audience arrived one by one, and, as master of ceremonies, it fell to me to greet them and place them as much at ease as the natural tension of the occasion would permit. Garrick spoke a word or two to each, but was still busy putting the finishing touches on the preparations for the "entertainment," as he called it facetiously, which he had arranged.
"Before I put to the test a rather novel combination which I have arranged," began Garrick, when they had all been seated, "I want to say a few words about some of the discoveries I have already made in this remarkable case."
He paused a moment to make sure that he had our attention, but it was unnecessary. We were all hanging eagerly on his words.
"There is, I believe," he resumed slowly, "no crime that is ever without a clew. The slightest trace, even a drop of blood no larger than a pin-head, may suffice to convict a murderer. So may a single hair found on the clothing of a suspect. In this case," he added quickly, "it is the impression made by the hammer of a pistol on the shell of a cartridge which leads unescapably to one conclusion."
The idea was so startling that we followed Garrick\'s every word as if weighted with tremendous importance, as indeed it was in the clearing up of this mysterious affair.
"I have made a collection from time to time," he pursued, "of the various exploded cartridges, the bullets, and the weapons left behind by the perpetrator of the dastardly series of crimes, from the shooting of the stool pigeon of the police, Rena Taylor, and the stealing of Mr. Warrington\'s car, down to the peculiar events of last night up in the Ramapos and the running fight through the streets of New York in taxicabs this morning.
"I have studied this evidence with the microscope and the microphotographic apparatus. I have secured excellent microphotographs of the marks made by various weapons on the cartridges and bullets. Taking those used in the commission of the greater crimes in this series, I find that the marks are the same, apparently, whether the gun shot off a bullet of wax or tallow which became liquid in the body, whether it discharged a stupefying gas, or whether the deadly anaesthetic bullet was fired. I have obtained a gun"—he threw it on the table with a clang—"the marks from the hammer of which correspond with the marks made on all the cartridges I have mentioned. One person owned that gun and used it. That is proved. It remains only to connect that gun positively and definitely, as a last link, with that person."
I noticed with a start that the revolver still had a stout cord tied to it.
As he concluded, Garrick had begun fitting a curious little device to each of our forearms. It looked to me like an electrode consisting of large plates of German silver, covered with felt and saturated with salt solution. From each electrode wires ran across the floor to some hidden apparatus.
"Back of this screen," he went on, indicating it in the corner of the room, "I have placed what is known as the string galvanometer, invented, or, perhaps better, perfected by Dr. Einthoven, of Leyden. It was designed primarily for the study of the beating of the heart in cases of disease, but it also may be used to record and study emotions as well,—love and hate, fear, joy, anger, remorse, all are revealed by this uncanny, cold, ruthlessly scientific instrument.
"The machine is connected by wires to each of you, and will make what are called electrocardiographs, in which every emotion, every sentiment, every passion is recorded inevitably, inexorably. For, the electric current that passes from each of you to the machine over these wires carrying the record of the secrets of your hearts is one of the feeblest currents known to science. Yet it can be caught and measured. The dynamo which generates this current is not a huge affair of steel castings and endless windings of copper wire. It is merely the heart of the sitter.
"The heart makes only one three-thousandth of a volt of electricity at each beat. It would take thousands of hearts to light one electric light, hundreds of thousands to run one trolley car. Yet just that slight little current from the heart is enough to sway a gossamer strand of quartz fibre in what I may call my \'heart station\' here. This current, as I have told you, passes from each of you over a wire and vibrates a fine quartz fibre in unison with it, one of the most delicate bits of mechanism ever made, recording the result on a photographic film by means of a beam of light reflected from a delicate mirror."
We sat spellbound as Garrick unfolded the dreadful, awe-inspiring possibilities of the machine behind the screen. He walked slowly to the back of the room.
"Now, here I have one of the latest of the inventions of the Wizard of West Orange—Edison," he resumed. "It is, as you perhaps have already guessed, the latest product of this genius of sound and sight, the kinetophone, the machine that combines moving pictures with the talking machine."
A stranger stepped in from an outer office. He was the skilled operator of the kinetophone, whom Garrick had hired. In a few terse sentences he explained that back of a curtain which he pulled down before us was a phonograph with a megaphone, that from his booth behind us he operated the picture films, and that the two were absolutely synchronized.
A moment later a picture began to move on the screen. Sounds and voices seemed to emerge as if from the very screen itself. There, before us, we saw a gambling joint operating in full blast. It was not the Forty-eighth Street resort. But it was strongly reminiscent of it. From the talking machine proceeded all the noises familiar to such a scene.
Garrick had moved behind the screen that cut off our view of the galvanometer. One after another, he was studying the emotions of each of his audience.
Suddenly the scene changed. A door was burst in, cards and gambling paraphernalia were scattered about and hidden, men rushed to escape, and the sounds were much like those on the night of the raid. Garrick was still engrossed in the study of what the galvanometer was showing.
The film stopped. Without warning, the operator started another. It was a group of men and women playing cards. A man entered, and engaged in conversation with one of the women who was playing. They left the room.
The next scene was in an entirely different room. But the connection which was implied with the last scene was obvious. Different actors entered the room, a man and a woman. There was a dispute—there was a crack of a revolver—and the woman fell. People rushed in. Everything was done to hide the crime. The girl was carried out into a waiting automobile, propped in as if overcome by alcohol and whisked away. I found myself almost looking to see if the car was of the make of Warrington\'s, so great was the impression the scene made on me. Of course it was not, but it all seemed so real that one might be pardoned for expecting the impossible, especially when her body was thrown, with many a muttered imprecation, by the roadside, and in the last picture the man was cleaning the exploded gun. One single still picture followed. It was a huge, enlarged cartridge.
I followed the thing with eager eyes and ears. From a long list of canned and reeled plays, Garrick had selected here and there such scenes and acts as, interspersed with a few single, original pictures of his own, like the cartridge, would serve best to recapitulate the very case which we had been investigating. It carried me along step by step, wonderfully.
Another moving and talking picture was under way. This time it seemed to be a race between two automobiles. They were tearing along, and the sound of the rapidly working cylinders was most real. The rearmost was rapidly overhauling that in front. Imagine our surprise as it crept up on the other to see the driver rise, whip out a pistol, and fire point blank at the other as he dashed ahead, and the picture stopped.
A suppressed scream escaped Violet Winslow. It was too much like what had happened to Mortimer Warrington for her to repress the shudder that swept over her, and an involuntary movement toward him to make sure that it was not real.
Still Garrick did not move from his post at the galvanometer. He was taking no chances. He had us thrilled, tense, and he meant to take advantage to the full in reading the truth in the dramatic situation he had so skilfully created.
Another picture started almost on the heels of the last. It was of the robbery of a safe. Then came another, a firebug at work in starting a conflagration. We could hear the crackling of flames, the shouts of the people, the clang of bells, and the hasty tread of the firemen as they advanced and put out the blaze. The film play was one of those which never fail to attract, where the makers had gone to the utmost extent of realism and had actually set fire to a house to get the true effect.
The next was a scene from a detective play, pure and simple, in which that marvellous little instrument which had served us in such good stead in this case was played up strongly, the detectaphone. Then followed a scene from another play in which a young girl was kidnapped and rescued by her lover just in the nick of time. Nothing could have been selected to arouse the feelings of the little audience to a higher pitch.
The last of the series, which I knew was to be a climax, was not an American picture. It was quite evidently made in Paris and was from actual life. I myself had been startled when the title was announced by the voice and on the screen simultaneously, "The Siege of the Motor Bandits by the Paris Police."
It was terrific. It began with the shouts of the crowd urging on the police, the crack of revolvers and guns from a little house or garage in the suburbs, the advance and retreat of the gendarmes on the stronghold. Back and forth the battle waged. One could hear the sharp orders of the police, the shrill taunts of the bandits, the sounds of battle.
Then at a point where the bandits seemed to have beaten off the attack successfully, there came an automobile. From it I could see the police take an object which I now knew must be a Mathiot gun. The huge thing was set up and carefully aimed. Then with a dull roar it was fired.
We could see the bomb hurtling through the air, see it strike the little house with a clou............