The alarm wakened me all right, but to my surprise Kennedy had already gone, ahead of it. I dressed hurriedly, bolted an early breakfast, and made my way to Trimble's. He was not there, and I had about concluded to try the laboratory, when I saw him pulling up in a cab from which he took several packages. Donnelly had joined us by this time, and together we rode up in the elevator to the jewelry department. I had never seen a department-store when it was empty, but I think I should like to shop in one under those conditions. It seemed incredible to get into the elevator and go directly to the floor you wanted.

The jewelry department was in the front of the building on one of the upper floors, with wide windows through which the bright morning light streamed attractively on the glittering wares that the clerks were taking out of the safes and disposing to their best advantage. The store had not opened yet, and we could work unhampered.

From his packages, Kennedy took three black boxes. They seemed to have an opening in front, while at one side was a little crank, which, as nearly as I could make out, was operated by clockwork released by an electric contact. His first problem seemed to be to dispose the boxes to the best advantage at various angles about the counter where the Kimberley Queen was on exhibition. With so much bric-a-brac and other large articles about, it did not appear to be very difficult to conceal the boxes, which were perhaps four inches square on the ends and eight inches deep. From the boxes with the clockwork attachment at the side he led wires, centring at a point at the interior end of the aisle where we could see but would hardly be observed by any one standing at the jewelry counter.

Customers had now begun to arrive, and we took a position in the background, prepared for a long wait. Now and then Donnelly casually sauntered past us. He and Craig had disposed the store detectives in a certain way so as to make their presence less obvious, while the clerks had received instructions how to act under the circumstance that a suspicious person was observed.

Once when Donnelly came up he was quite excited. He had just received a message from Bentley that some of the stolen property, the pearls, probably, from the dog collar that had been taken from Shorham's, had been offered for sale by a "fence" known to the police as a former confederate of Annie Grayson.

"You see, that is one great trouble with them all," he remarked, with his eye roving about the store in search of anything irregular. "A shoplifter rarely becomes a habitual criminal until after she passes the age of twenty-five. If they pass that age without quitting, there is little hope of their getting right again, as you see. For by that time they have long since begun to consort with thieves of the other sex."

The hours dragged heavily, though it was a splendid chance to observe at leisure the psychology of the shopper who looked at much and bought little, the uncomfortableness of the men who had been dragged to the department store slaughter to say "Yes" and foot the bills, a kaleidoscopic throng which might have been interesting if we had not been so intent on only one matter.

Kennedy grasped my elbow in vise-like fingers. Involuntarily I looked down at the counter where the Kimberley Queen reposed in all the trappings of genuineness. Mrs. Willoughby had arrived again.

We were too far off to observe distinctly just what was taking place, but evidently Mrs. Willoughby was looking at the gem. A moment later another woman sauntered casually up to the counter. Even at a distance I recognised Annie Grayson. As nearly as I could make out they seemed to exchange remarks. The clerk answered a question or two, then began to search for something apparently to show them. Every one about them was busy, and, obedient to instructions from Donnelly, the store detectives were in the background.

Kennedy was leaning forward watching as intently as the distance would permit. He reached over and pressed the button near him.

After a minute or two the second woman left, followed shortly by Mrs. Willoughby herself. We hurried over to the counter, and Kennedy seized the box containing the Kimberley Queen. He examined it carefully. A flaw in the paste jewel caught his eye.

"There has been a substitution here," he cried. "See! The paste jewel which we used was flawless; this has a little carbon spot here on the side."

"One of my men has been detailed to follow each of them," whispered
Donnelly. "Shall I order them to bring Mrs. Willoughby and Annie
Grayson to the superintendent's office and have them searched?"

"No," Craig almost shouted. "That would spoil everything. Don't make a move until I get at the real truth of this affair."

The case was becoming more than ever a puzzle to me, but there was nothing left for me to do but to wait until Kennedy was ready to accompany Dr. Guthrie to the Willoughby house. Several times he tried to reach the doctor by telephone, but it was not until the middle of the afternoon that he succeeded.

"I shall be quite busy the rest of the afternoon, Walter," remarked Craig, after he had made his appointment with Dr. Guthrie. "If you will meet me out at the Willoughbys' at about eight o'clock, I shall be much obliged to you."

I promised, and tried to devote myself to catching up with my notes, which were always sadly behind when Kennedy had an important case. I did not succeed in accomplishing much, however.

Dr. Guthrie himself met me at the door of the beautiful house on Woodridge Avenue and with a hearty handshake ushered me into the large room in the right wing outside of which we had placed the telegraphone two nights before. It was the library.

We found Kennedy arranging an instrument in the music-room which adjoined the library. From what little knowledge I have of electricity I should have said it was, in part at least, a galvanometer, one of those instruments which register the intensity of minute electric currents. As nearly as I could make out, in this case the galvanometer was so arranged that its action swung to one side or the other a little concave mirror hung from a framework which rested on the table. Directly in front of it was an electric light, and the reflection of the light was caught in the mirror and focused by its concavity upon a point to one side of the light. Back of it was a long strip of ground glass and an arrow point, attached to which was a pen which touched a roll of paper.

On the large table in the library itself Kennedy had placed in the centre a transverse board partition, high enough so that two people seated could see each other's faces and converse over it, but could not see each other's hands. On one side of the partition were two metal domes which were fixed to a board set on the table. On the other side, in addition to space on which he could write, Kennedy had arranged what looked like one of these new miniature moving-picture apparatuses operated by electricity. Indeed, I felt that it must be that, for directly in front of it, hanging on the wall, in plain view of any one seated on the side of the table containing the metal domes, was a large white sheet.

The time for the experiment, whatever its nature might be, had at last arrived, and Dr. Guthrie introduced Mr. and Mrs. Willoughby to us as specialists whom he had persuaded with great difficulty to come down from New York. Mr. Willoughby he requested to remain outside until after the tests. She seemed perfectly calm as she greeted us, and looked with curiosity at the paraphernalia which Kennedy had installed in her library. Kennedy, who was putting some finishing touches on it, was talking in a low voice to reassure her.

"If you will sit here, please, Mrs. Willoughby, and place your hands on these two brass domes—there, that's it. This is just a little arrangement to test your nervous condition. Dr. Guthrie, who understands it, will take his position outside in the music-room at that other table. Walter, just switch off that light, please.

"Mrs. Willoughby, I may say that in testing, say, the memory, we psychologists have recently developed two tests, the event test, where something is made to happen before a person's eyes and later he is asked to describe it, and the picture test, where a picture is shown for a certain length of time, after which the patient is also asked to describe what was in the picture. I have endeavoured to combine these two ideas by using the moving-picture machine which you see here. I am going to show three reels of films."

As nearly as I could make out Kennedy had turned on the light in the lantern on his side of the table. As he worked over the machine, which for the present served to distract Mrs. Willoughby's attention from herself, he was asking her a series of questions. From my position I could see that by the light of the machine he was recording both the questions and the answers, as well as the time registered to the fifth of a second by a stop-watch. Mrs. Willoughby could not see what he was doing under the pretence of working over his little moving-picture machine.

He had at last finished the questioning. Suddenly, without any warning, a picture began to play on the sheet. I must say that I was startled myself. It represented the jewelry counter at Trimble's, and in it I could see Mrs. Willoughby herself in animated conversation with one of the clerks. I looked intently, dividing my attention between the picture and the woman. But so far as I could see there was nothing in this first film that incriminated either of them.

Kennedy started on the second without stopping. It was practically the same as the first, only taken from a different angle.

He had scarcely run it half through when Dr. Guthrie opened the door.

"I think Mrs. Willoughby must have taken her hands off the metal domes," he remarked; "I can get no record out here."

I had turned when he opened the door, and now I caught a glimpse of Mrs. Willoughby standing, her hands pressed tightly to her head as if it were bursting, and swaying as if she would faint. I do not know what the film was showing at this point, for Kennedy with a quick movement shut it off and sprang to her side.

"There, that will do, Mrs. Willoughby. I see that you are not well," he soothed. "Doctor, a little something to quiet her nerves. I think we can complete our work merely by comparing notes. Call Mr. Willoughby, Walter. There, sir, if you will take charge of your wife and perhaps take her for a turn or two in the fresh air, I think we can tell you in a few moments whether her condition is in any way serious or not."

Mrs. Willoughby was on the verge of hysterics as her husband supported her out of the room. The door had scarcely shut before Kennedy threw open a window and seemed to beckon into the darkness. As if from nowhere, Donnelly and Bentley sprang no and were admitted.

Dr. Guthrie had now returned from the music-room, bearing a sheet of paper on which was traced a long irregular curve at various points on which marginal notes had been written hastily.

Kennedy leaped directly into the middle of things with his characteristic ardour. "You recall," he began, "that no one seemed to know just who took the jewels in both the cases you first reported? 'Seeing is believing,' is an old saying, but in the face of such reports as you detectives gathered it is in a fair way to lose its force. And you were not at fault, either, for modern psychology is proving by experiments that people do not see even a fraction of the things they confidently believe they see.

"For example, a friend of mine, a professor in a Western university, has carried on experiments with scores of people and has not found one who could give a completely accurate description of what he had seen, even in the direct testimony; while under the influence of questions, particularly if they were at all leading, witnesses all showed extensive inaccuracies in one or more particulars, and that even though they are in a more advantageous position for giving reports than were your clerks who were not prepared. Indeed, it is often a wonder to me that witnesses of ordinary events who are called upon in court to relate what they saw after a considerable lapse of time are as accurate as they are, considering the questioning they often go through from interested parties, neighbours and friends, and the constant and often biased rehearsing of the event. The court asks the witness to tell the truth, the whole truth, and nothing but the truth. How can he? In fact, I am often surprised that there is such a resemblance between the testimony and the actual facts of the case!

"But I have here a little witness that never lies, and, mindful of the fallibility of ordinary witnesses, I called it in. It is a new, compact, little motion camera which has just been perfected to do automatically what the big moving-picture making cameras do."

He touched one of the little black boxes such as we had seen him install in the jewelry department at Trimble's.

"Each of these holds one hundred and sixty feet of film," he resumed, "enough to last three minutes, taking, say, sixteen pictures to the foot and running about one foot a second. You know that less than ten or eleven pictures a second affect the retina as separate, broken pictures. The use of this compact little motion camera was suggested to me by an ingenious but cumbersome invention recently offered to the police in Paris—the installation on the clock-towers in various streets of cinematograph apparatus directed by wireless. The motion camera as a detective has now proved its value. I have here three films taken at Trimble's, from different angles, and they clearly show exactly what actually occurred while Mrs. Willoughby and Annie Grayson were looking at the Kimberley Queen."

He paused as if analysing the steps in his own mind. "The telegraphone gave me the first hint of the truth," he said. "The motion camera brought me a step nearer, but without this third instrument, while I should have been successful, I would not have got at the whole truth."

He was fingering the apparatus on the library table connected with that in the music-room. "This is the psychometer for testing mental aberrations," he explained. "The scientists who are using it to-day are working, not with a view to aiding criminal jurisprudence, but with the hope of making such discoveries that the mental health of the race may be bettered. Still, I believe that in the study of mental diseases these men are furnishing the knowledge upon which future criminologists will build to make the detection of crime an absolute certainty. Some day there will be no jury, no detectives, no witnesses, no attorneys. The state will merely submit all suspects to tests of scientific instruments like these, and as these instruments can not make mistakes or tell lies their evidence will be conclusive of guilt or innocence.

"Already the psychometer is an actual working fact. No living man can conceal his emotions from the uncanny instrument. He may bring the most gigantic of will-powers into play to conceal his inner feelings and the psychometer will record the very work which he makes this will-power do.

"The machine is based upon the fact that experiments have proved that the human body's resistance to an electrical current is increased with the increase of the emotions. Dr. Jung, of Zurich, thought that it would be a very simple matter to record these varying emotions, and the psychometer is the result—simple and crude to-day compared with what we have a right to expect in the future.

"A galvanometer is so arranged that its action swings a mirror from side to side, reflecting a light. This light falls on a ground-glass scale marked off into centimetres, and the arrow is made to follow the beam of light. A pen pressing down on a metal drum carrying a long roll of paper revolved by machinery records the variations. Dr. Guthrie, who had charge of the recording, simply sat in front of the ground glass and with the arrow point followed the reflection of the light as it moved along the scale, in this way making a record on the paper on the drum, which I see he is now holding in his hand.

"Mrs. Willoughby, the subject, and myself, the examiner, sat here, facing each other over this table. Through those metal domes on which she was to keep her hands she received an electric current so weak that it could not be felt even by the most sensitive nerves. Now with every increase in her emotion, either while I was putting questions to her or showing her the pictures, whether she showed it outwardly or not, she increased her body's resistance to the current that was being passed in through her hands. The increase was felt by the galvanometer connected by wires in the music-room, the mirror swung, the light travelled on the scale, the arrow was moved by Dr. Guthrie, and her varying emotions were recorded indelibly upon the revolving sheet of paper, recorded in such a way as to show their intensity and reveal to the trained scientist much of the mental condition of the subject."

Kennedy and Dr. Guthrie now conversed in low tones. Once in a while I could catch a scrap of the conversation—"not an epileptic," "no abnormal conformation of the head," "certain mental defects," "often the result of sickness or accident."

"Every time that woman appeared there was a most peculiar disturbance," remarked Dr. Guthrie as Kennedy took the roll of paper from him and studied it carefully.

At length the light seemed to break through his face.

"Among the various kinds of insanity," he said, slowly measuring his words, "there is one that manifests itself as an irresistible impulse to steal. Such terms as neuropath and kleptomaniac are often regarded as rather elegant names for contemptible excuses invented by medical men to cover up stealing. People are prone to say cynically, 'Poor man's sins; rich man's diseases.' Yet kleptomania does exist, and it is easy to make it seem like crime when it is really persistent, incorrigible, and irrational stealing. Often it is so great as to be incurable. Cases have been recorded of clergymen who were kleptomaniacs and in one instance a dying victim stole the snuffbox of his confessor.

"It is the pleasure and excitement of stealing, not the desire for the object stolen, which distinguishes the kleptomaniac from the ordinary thief. Usually the kleptomaniac is a woman, with an insane desire to steal for the mere sake of stealing. The morbid craving for excitement which is at the bottom of so many motiveless and useless crimes, again and again has driven apparently sensible men and women to ruin and even to suicide. It is a form of emotional insanity, not loss of control of the will, but perversion of the will. Some are models in their lucid intervals, but when the mania is on them they cannot resist. The very act of taking constitutes the pleasure, not possession. One must take into consideration many things, for such diseases as kleptomania belong exclusively to civilisation; they are the product of an age of sensationalism. Naturally enough, woman, with her delicately balanced nervous organisation, is the first and chief offender."

Kennedy had seated himself at the table and was writing hastily. When he had finished, he held the papers in his hand to dry.

He handed one sheet each to Bentley and Donnelly. We crowded about. Kennedy had simply written out two bills for the necklace and the collar of pearls.

"Send them in to Mr. Willoughby," he added. "I think he will be glad to pay them to hush up the scandal."

We looked at each other in amazement at the revelation.

"But what about Annie Grayson?" persisted Donnelly.

"I have taken care of her," responded Kennedy laconically. "She is already under arrest. Would you like to see why?"

A moment later we had all piled into Dr. Guthrie's car, standing at the door.

At the cosy little Grayson villa we found two large eyed detectives and a very angry woman waiting impatiently. Heaped up on a table in the living room was a store of loot that readily accounted for the ocular peculiarity of the detectives.

The jumble on the table contained a most magnificent collection of diamonds, sapphires, ropes of pearls, emeralds, statuettes, and bronze and ivory antiques, books in rare bindings, and other baubles which wealth alone can command. It dazzled our eyes as we made a mental inventory of the heap. Yet it was a most miscellaneous collection. Beside a pearl collar with a diamond clasp were a pair of plain leather slippers and a pair of silk stockings. Things of value and things of no value were mixed as if by a lunatic. A beautiful neck ornament of carved coral lay near a half-dozen common linen handkerchiefs. A strip of silk hid a valuable collection of antique jewellery. Besides diamonds and precious stones by the score were gold and silver ornaments, silks, satins, laces, draperies, articles of virtu, plumes, even cutlery and bric-a-brac. All this must have been the result of countless excursions to the stores of New York and innumerable clever thefts.

We could only look at each other in amazement and wonder at the defiance written on the face of Annie Grayson.

"In all this strange tangle of events," remarked Kennedy, surveying the pile with obvious satisfaction, "I find that the precise instruments of science have told me one more thing. Some one else discovered Mrs. Willoughby's weakness, led her on, suggested opportunities to her, used her again and again, profited by her malady, probably to the extent of thousands of dollars. My telegraphone record hinted at that. In some way Annie Grayson secured the confidence of Mrs. Willoughby. The one took for the sake of taking; the other received for the sake of money. Mrs. Willoughby was easily persuaded by her new friend to leave here what she had stolen. Besides, having taken it, she had no further interest in it.

"The rule of law is that every one is responsible who knows the nature and consequences of his act. We have absolute proof that you, Annie Grayson, although you did not actually commit any of the thefts yourself, led Mrs. Willoughby on and profited by her. Dr. Guthrie will take care of the case of Mrs. Willoughby. But the law must deal with you for playing on the insanity of a kleptomaniac—the cleverest scheme yet of the queen of shoplifters."

As Kennedy turned nonchalantly from the detectives who had seized Annie
Grayson, he drew a little red folder from his pocket.

"You see, Walter," he smiled, "how soon one gets into a habit? I'm almost a regular commuter, now. You know, they are always bringing out these little red folders just when things grow interesting."

I glanced over his shoulder. He was studying the local timetable.

"We can get the last train from Glenclair if we hurry," he announced, stuffing the folder back into his pocket. "They will take her to Newark by trolley, I suppose. Come on."

We made our hasty adieux and escaped as best we could the shower of congratulations.

"Now for a rest," he said, settling back into the plush covered seat for the long ride into town, his hat down over his eyes and his legs hunched up against the back of the next seat. Across in the tube and uptown in a nighthawk cab we went and at last we were home for a good sleep.

"This promises to be an off-day," Craig remarked, the next morning over the breakfast table. "Meet me in the forenoon and we'll take a long, swinging walk. I feel the need of physical exercise."

"A mark of returning sanity!" I exclaimed.

I had become so used to being called out on the unexpected, now, that I almost felt that some one might stop us on our tramp. Nothing of the sort happened, however, until our return.

Then a middle-aged man and a young girl, heavily veiled, were waiting for Kennedy, as we turned in from the brisk finish in the cutting river wind along the Drive.

"Winslow is my name, sir," the man began, rising nervously as we entered the room, "and this is my only daughter, Ruth."

Kennedy bowed and we waited for the man to proceed. He drew his hand over his forehead which was moist with perspiration in spite of the season. Ruth Winslow was an attractive young woman, I could see at a glance, although her face was almost completely hidden by the thick veil.

"Perhaps, Ruth, I had better—ah—see these gentlemen alone?" suggested her father gently.

"No, father," she answered in a tone of forced bravery, "I think not. I can stand it. I must stand it. Perhaps I can help you in telling about the—the case."

Mr. Winslow cleared his throat.

"We are from Goodyear, a little mill-town," he proceeded slowly, "and as you doubtless can see we have just arrived after travelling all day."

"Goodyear," repeated Kennedy slowly as the man paused. "The chief industry, of course, is rubber, I suppose."

"Yes," assented Mr. Winslow, "the town centres about rubber. Our factories are not the largest but are very large, nevertheless, and are all that keep the town going. It is on rubber, also, I fear, that the tragedy which I am about to relate hangs. I suppose the New York papers have had nothing to say of the strange death of Bradley Cushing, a young chemist in Goodyear who was formerly employed by the mills but had lately set up a little laboratory of his own?"

Kennedy turned to me. "Nothing unless the late editions of the evening papers have it," I replied.

"Perhaps it is just as well," continued Mr. Winslow. "They wouldn't have it straight. In fact, no one has it straight yet. That is why we have come to you. You see, to my way of thinking Bradley Cushing was on the road to changing the name of the town from Goodyear to Cushing. He was not the inventor of synthetic rubber about which you hear nowadays, but he had improved the process so much that there is no doubt that synthetic rubber would soon have been on the market cheaper and better than the best natural rubber from Para.

"Goodyear is not a large place, but it is famous for its rubber and uses a great deal of raw material. We have sent out some of the best men in the business, seeking new sources in South America, in Mexico, in Ceylon, Malaysia and the Congo. What our people do not know about rubber is hardly worth knowing, from the crude gum to the thousands of forms of finished products. Goodyear is a wealthy little town, too, for its size. Naturally all its investments are in rubber, not only in our own mills but in companies all over the world. Last year several of our leading citizens became interested in a new concession in the Congo granted to a group of American capitalists, among whom was Lewis Borland, who is easily the local magnate of our town. When this group organised an expedition to explore the region preparatory to taking up the concession, several of the best known people in Goodyear accompanied the party and later subscribed for large blocks of stock.

"I say all this so that you will understand at the start just what part rubber plays in the life of our little community. You can readily see that such being the case, whatever advantage the world at large might gain from cheap synthetic rubber would scarcely benefit those whose money and labour had been expended on the assumption that rubber would be scarce and dear. Naturally, then, Bradley Cushing was not precisely popular with a certain set in Goodyear. As for myself, I am frank to admit that I might have shared the opinion of many others regarding him, for I have a small investment in this Congo enterprise myself. But the fact is that Cushing, when he came to our town fresh from his college fellowship in industrial chemistry, met my daughter."

Without taking his eyes off Kennedy, he reached over and patted the gloved hand that clutched the arm of the chair alongside his own. "They were engaged and often they used to talk over what they would do when Bradley's invention of a new way to polymerise isoprene, as the process is called, had solved the rubber question and had made him rich. I firmly believe that their dreams were not day dreams, either. The thing was done. I have seen his products and I know something about rubber. There were no impurities in his rubber."

Mr. Winslow paused. Ruth was sobbing quietly.

"This morning," he resumed hastily, "Bradley Cushing was found dead in his laboratory under the most peculiar circumstances. I do not know whether his secret died with him or whether some one has stolen it. From the indications I concluded that he had been murdered."

Such was the case as Kennedy and I heard it then.

Ruth looked up at him with tearful eyes wistful with pain, "Would Mr.
Kennedy work on it?" There was only one answer.