Problem

of

the Lost Radium

One ounce of radium! Within his open palm Professor Dexter held practically the world’s entire supply of that singular and seemingly inexhaustible force which was, and is, one of the greatest of all scientific riddles. So far as known there were only a few more grains in existence—four in the Curie laboratory in Paris, two in Berlin, two in St. Petersburg, one at Leland Stanford University and one in London. All the remainder was here—here in the Yarvard laboratory, a tiny mass lumped on a small piece of steel.

Gazing at this vast concentrated power Professor Dexter was a little awed and a little appalled at the responsibility which had suddenly devolved upon him, naturally enough with this culmination of a project which he had cherished for months. Briefly this had been to gather into one cohesive whole the many particles of the precious substance scattered over the world for the purpose of elaborate experiments as to its motive power practicability. Now here it was.

Its value, based on scarcity of supply, was incalculable. Millions of dollars would not replace it. Minute portions had come from the four quarters of the globe, in each case by special messenger, and each separate grain had been heavily insured by Lloyd’s at a staggering premium. It was only after months of labour, backed by the influence of the great university of Yarvard in which he held the chair of physics, that Professor Dexter had been able to accomplish his purpose.

At least one famous name had been loaned to the proposed experiments, that of the distinguished scientist and logician, Professor Augustus S. F. X. Van Dusen—so called The Thinking Machine. The interest of this master mind in the work was a triumph for Professor Dexter, who was young and comparatively unknown. The elder scientist—The Thinking Machine—was a court of last appeal in the sciences and from the moment his connection with Professor Dexter’s plans was announced his fellows all over the world had been anxiously awaiting a first word.

Naturally the task of gathering so great a quantity of radium had not been accomplished without extensive, and sometimes sensational, newspaper comment all over the United States and Europe. It was not astonishing, therefore that news of the receipt of the final portion of the radium at Yarvard had been known in the daily press and with it a statement that Professors Van Dusen and Dexter would immediately begin their experiments.

The work was to be done in the immense laboratory at Yarvard a high-ceilinged room with roof partially of glass, and with windows set high in the walls far above the reach of curious eyes. Full preparations had been made;—the two men were to work together, and a guard was to be stationed at the single door. This door led into a smaller room, a sort of reception hall, which in turn connected with the main hallway of the building.

Now Professor Dexter was alone in the laboratory, waiting impatiently for The Thinking Machine and turning over in his mind the preliminary steps in the labour he had undertaken. Every instrument was in place, all else was put aside for these experiments, which were either to revolutionize the motive power of the world or else demonstrate the utter uselessness of radium as a practical force.

Professor Dexter’s line of thought was interrupted by the appearance of Mr. Bowen, one of the instructors of the University.

“A lady to see you, Professor,” he said as he handed him a card. “She said it was a matter of great importance to you.”

Professor Dexter glanced at the card as Mr. Bowen turned and went out through the small room into the main hallway. The name, Mme. Therese du Chastaigny, was wholly unfamiliar. Puzzled a little and perhaps impatient too, he carefully laid the steel with its burden of radium on the long table, and started out into the reception room. Almost in the door he stumbled against something, recovered his equilibrium with an effort and brought up with an undignified jerk.

The colour mounted to his modest ears as he heard a woman laugh—a pleasant, musical, throaty sort of ripple that under other circumstances would have been agreeable. Now, being directed at his own discomfiture, it was irritating, and the Professor’s face tingled a little as a tall woman arose and came towards him.

“Please pardon me,” she said contritely, but there was still a flicker of a smile upon her red lips. “It was my carelessness. I should not have placed my suit case in the door.” She lifted it easily and replaced it in that identical position. “Or perhaps,” she suggested, inquiringly, “someone else coming out might stumble as you did?”

“No,” replied the Professor, and he smiled a little through his blushes. “There is no one else in there.”

As Mme. du Chastaigny straightened up, with a rustle of skirts, to greet him Professor Dexter was somewhat surprised at her height and at the splendid lines of her figure. She was apparently of thirty years and seemed from a casual glance, to be five feet nine or ten inches tall. In addition to a certain striking indefinable beauty she was of remarkable physical power if one might judge from her poise and manner. Professor Dexter glanced at her and then at the card inquiringly.

“I have a letter of introduction to you from Mme. Curie of France,” she explained as she produced it from a tiny chatelaine bag. “Shall we go over here where the light is better?”

She handed the letter to him and together they seated themselves under one of the windows near the door into the outer hallway. Professor Dexter pulled up a light chair facing her and opened the letter. He glanced through it and then looked up with a newly kindled interest in his eyes.

“I should not have disturbed you,” Mme. du Chastaigny explained pleasantly, “had I not known it was a matter of the greatest possible interest to you.”

“Yes?” Professor Dexter nodded.

“It’s radium,” she continued. “It just happens that I have in my possession practically an ounce of radium of which the world of science has never heard.”

“An ounce of radium!” repeated Professor Dexter, incredulously. “Why, Madame, you astonish, amaze me. An ounce of radium?”

He leaned further forward in his chair and waited expectantly while Mme. du Chastaigny coughed violently. The paroxysm passed after a moment.

“That is my punishment for laughing,” she explained, smilingly. “I trust you will pardon me. I have a bad throat—and it was quick retribution.”

“Yes, yes,” said the other courteously, “but this other—it’s most interesting. Please tell me about it.”

Mme. du Chastaigny made herself comfortable in the chair, cleared her throat, and began.

“It’s rather an unusual story,” she said apologetically, “but the radium came into my possession in quite a natural manner. I am English, so I speak the language, but my husband was French as my name indicates, and, he, like you, was a scientist. He was little known to the world at large, however, as he was not connected with any institution. His experiments were undertaken for amusement and gradually led to a complete absorption of his interest. We were not wealthy as Americans count it, but we were comfortably well off.

“That much for my affairs. The letter I gave you from Mme. Curie will tell you the rest as to who I am. Now when the discovery of radium was made by M. and Mme. Curie my husband began some investigations along the same line and they proved to be remarkably successful. His efforts were first directed towards producing radium, with what object, I was not aware at that time. In the course of months he made grain after grain by some process unlike that of the Curies’, and incidentally he spent practically all our little fortune. Finally he had nearly an ounce.”

“Most interesting!” commented Professor Dexter. “Please go on.”

“It happened that during the production of the last quarter of an ounce, my husband contracted an illness which later proved fatal,” Mme. du Chastaigny resumed after a slight pause, and her voice dropped. “I did not know the purpose of his experiments; I only knew what they had been and their comparative cost. On his death bed he revealed this purpose to me. Strangely enough it was identical with yours as the newspapers have announced it—that is, the practicability of radium as a motive power. He was at work on plans looking to the utilization of its power when he died but these plans were not perfected and unfortunately were in such shape as to be unintelligible to another.”

She paused and sat silent for a moment. Professor Dexter watching her face, traced a shadow of grief and sorrow there and his own big heart prompted a ready sympathy.

“And what,” he asked, “was your purpose in coming to me now?”

“I know of the efforts you have made and the difficulties you have encountered in gathering enough radium for the experiments you have in mind,” Mme. du Chastaigny continued, “and it occurred to me that what I have, which is of no possible use to me, might be sold to you or to the university. As I said, there is nearly an ounce of it. It is where I can put my hands on it, and you of course are to make the tests to prove it is what it should be.”

“Sell it?” gasped Professor Dexter. “Why, Madame, it’s impossible. The funds of the college are not so plentiful that the vast fortune necessary to purchase such a quantity would be forth-coming.”

A certain hopeful light in the face of the young woman passed and there was a quick gesture of her hands which indicated disappointment.

“You speak of a vast fortune,” she said at last. “I could not hope, of course, to realize anything like the actual value of the substance—a million perhaps? Only a few hundred thousands? Something to convert into available funds for me the fortune which has been sunk.”

There was almost an appeal in her limpid voice and Professor Dexter considered the matter deeply for several minutes as he stared out the window.

“Or perhaps,” the woman hurried on after a moment, “it might be that you need more radium for the experiments you have in hand now, and there might be some sum paid me for the use of what I have? A sort of royalty? I am willing to do anything within reason.”

Again there was a long pause. Ahead of him, with this hitherto unheard of quantity of radium available, Professor Dexter saw rosy possibilities in his chosen work. The thought gripped him more firmly as he considered it. He could see little chance of a purchase—but the use of the substance during his experiments! That might be arranged.

“Madame,” he said at last, “I want to thank you deeply for coming to me. While I can promise nothing definite I can promise that I will take up the matter with certain persons who may be able to do something for you. It’s perfectly astounding. Yes, I may say that I will do something, but I shall perhaps, require several days to bring it about. Will you grant me that time?”

Mme. du Chastaigny smiled.

“I must of course,” she said, and again she went off into a paroxysm of coughing, a distressing, hacking outburst which seemed to shake her whole body. “Of course,” she added, when the spasm passed, “I can only hope that you can do something either in purchasing or using it.”

“Could you fix a definite price for the quantity you have—that is a sale price—and another price merely for its use?” asked Professor Dexter.

“I can’t do that offhand of course, but here is my address on this card—Hotel Teutonic. I expect to remain there for a few days and you may reach me any time. Please, now please,” and again there was a pleading note in her voice, and she laid one hand on his arm, “don’t hesitate to make any offer to me. I shall be only too glad to accept it if I can.”

She arose and Professor Dexter stood beside her.

“For your information,” she went on, “I will explain that I only arrived in this country yesterday by steamer from Liverpool and my need is such that within another six months I shall be absolutely dependent upon what I may realize from the radium.”

She crossed the room, picked up the suit case and again she smiled, evidently at the recollection of Professor Dexter’s awkward stumble. Then with her burden she turned to go.

“Permit me, Madame,” suggested Professor Dexter, quickly as he reached for the bag.

“Oh no, it is quite light,” she responded easily.

There were a few commonplaces and then she went out. Gazing through the window after her Professor Dexter noted, with certain admiration in his eyes the graceful strong lines of her figure as she entered a carriage and was driven away. He stood deeply thoughtful for a minute considering the possibilities arising from her casual announcement of the existence of this unknown radium.

“If I only had that too,” he muttered as he turned and re-entered his work room.

An instant later, a cry—a wild amazed shriek—came from the laboratory and Professor Dexter, with pallid face, rushed out through the reception room and flung open the door into the main hallway. Half a dozen students gathered about him and from across the hall Mr. Bowen, the instructor, appeared with startled eyes.

“The radium is gone—stolen!” gasped Professor Dexter.

The members of the little group stared at one another blankly while Professor Dexter raved impotently and ran his fingers through his hair. There were questions and conjectures; a babble was raging about him when a new figure loomed up in the picture. It was that of a small man with an enormous yellow head and an eternal petulant droop to the corners of his mouth. He had just turned a corner in the hall.

“Ah, Professor Van Dusen,” exclaimed Professor Dexter, and he seized the long, slender hand of The Thinking Machine in a frenzied grip.

“Dear me! Dear me!” complained The Thinking Machine as he sought to extract his fingers from the vice. “Don’t do that. What’s the matter?”

“The radium is gone—stolen!” Professor Dexter explained.

The Thinking Machine drew back a little and squinted aggressively into the distended eyes of his fellow scientist.

“Why that’s perfectly silly,” he said at last. “Come in, please, and tell me what happened.”

With perspiration dripping from his brow and hands atremble, Professor Dexter followed him into the reception room, whereupon The Thinking Machine turned, closed the door into the hallway and snapped the lock. Outside Mr. Bowen and the students heard the click and turned away to send the astonishing news hurtling through the great university. Inside Professor Dexter sank down on a chair with staring eyes and nervously twitching lips.

“Dear me, Dexter, are you crazy?” demanded The Thinking Machine irritably. “Compose yourself. What happened? What were the circumstances of the disappearance?”

“Come—come in here—the laboratory and see,” suggested Professor Dexter.

“Oh, never mind that now,” said the other impatiently. “Tell me what happened?”

Professor Dexter paced the length of the small room twice then sat down again, controlling himself with a perceptible effort. Then, ramblingly but completely, he told the story of Mme. du Chastaigny’s call, covering every circumstance from the time he placed the radium on the table in the laboratory until he saw her drive away in the carriage. The Thinking Machine leaned back in his chair with squint eyes upturned and slender white fingers pressed tip to tip.

“How long was she here?” he asked at the end.

“Ten minutes, I should say,” was the reply.

“Where did she sit?”

“Right where you are, facing the laboratory door.”

The Thinking Machine glanced back at the window behind him.

“And you?” he asked.

“I sat here facing her.”

“You know that she did not enter the laboratory?”

“I know it, yes,” replied Professor Dexter promptly. “No one save me has entered that laboratory today. I have taken particular pains to see that no one did. When Mr. Bowen spoke to me I had the radium in my hand. He merely opened the door, handed me her card and went right out. Of course it’s impossible that——”

“Nothing is impossible, Mr. Dexter,” blazed The Thinking Machine suddenly. “Did you at any time leave Mme. du Chastaigny in this room alone?”

“No, no,” declared Dexter emphatically. “I was looking at her every moment she was here; I did not put the radium out of my hand until Mr. Bowen was out of this room and in the hallway there. I then came into this room and met her.”

For several minutes The Thinking Machine sat perfectly silent, squinting upward while Professor Dexter gazed into the inscrutable face anxiously.

“I hope,” ventured the Professor at last, “that you do not believe it was any fault of mine?”

The Thinking Machine did not say.

“What sort of a voice has Mme. du Chastaigny?” he asked instead.

The Professor blinked a little in bewilderment.

“An ordinary voice—the low voice of a woman of education and refinement,” he replied.

“Did she raise it at any time while talking?”

“No.”

“Perhaps she sneezed or coughed while talking to you?”

Unadulterated astonishment was written on Professor Dexter’s face.

“She coughed, yes, violently,” he replied.

“Ah!” exclaimed The Thinking Machine and there was a flash of comprehension in the narrow blue eyes. “Twice, I suppose?”

Professor Dexter was staring at the scientist blankly.

“Yes, twice,” he responded.

“Anything else?”

“Well, she laughed I think.”

“What was the occasion of her laughter?”

“I stumbled over a suit case she had set down by the laboratory door there.”

The Thinking Machine absorbed that without evidence of emotion, then reached for the letter of introduction which Mme. du Chastaigny had given to Professor Dexter and which he still carried crumpled up in his hand. It was a short note, just a few lines in French, explaining that Mme. du Chastaigny desired to see Professor Dexter on a matter of importance.

“Do you happen to know Mme. Curie’s handwriting?” asked The Thinking Machine after a cursory examination. “Of course you had some correspondence with her about this work?”

“I know her writing, yes,” was the reply. “I think that is genuine, if that’s what you mean.”

“We’ll see after a while,” commented The Thinking Machine.

He arose and led the way into the laboratory. There Professor Dexter indicated to him the exact spot on the work table where the radium had been placed. Standing beside it he made some mental calculation as he squinted about the room, at the highly placed windows, the glass roof above, the single door. Then wrinkles grew in his tall brow.

“I presume all the wall windows are kept fastened?”

“Yes, always.”

“And those in the glass roof?”

“Yes.”

“Then bring me a tall step-ladder please!”

It was produced after a few minutes. Professor Dexter looked on curiously and with a glimmer of understanding as The Thinking Machine examined each catch on every window, and tapped the panes over with a pen-knife. When he had examined the last and found all locked he came down the ladder.

“Dear me!” he exclaimed petulantly. “It’s perfectly extraordinary—most extraordinary. If the radium was not stolen through the reception room, then—then——” He glanced around the room again.

Professor Dexter shook his head. He had recovered his self-possession somewhat, but his bewilderment left him helpless.

“Are you sure, Professor Dexter,” asked The Thinking Machine at last coldly, “are you sure you placed the radium where you have indicated?”

There was almost an accusation in the tone and Professor Dexter flushed hotly.

“I am positive, yes,” he replied.

“And you are absolutely certain that neither Mr. Bowen nor Mme. du Chastaigny entered this room?”

“I am absolutely positive.”

The Thinking Machine wandered up and down the long table apparently without any interest, handling the familiar instruments and glittering appliances as a master.

“Did Mme. du Chastaigny happen to mention any children?” he at last asked, irrelevantly.

Professor Dexter blinked again.

“No,” he replied.

“Adopted or otherwise?”

“No.”

“Just what sort of a suit case was that she carried?”

“Oh, I don’t know,” replied Professor Dexter. “I didn’t particularly notice. It seemed to be about the usual kind of a suit case—sole leather I imagine.”

“She arrived in this country yesterday you said?”

“Yes.”

“It’s perfectly extraordinary,” The Thinking Machine grunted. Then he scribbled a line or two on a scrap of paper and handed it to Professor Dexter.

“Please have this sent by cable at once.”

Professor Dexter glanced at it. It was:

“Mme. Curie, Paris:

“Did you give Mme. du Chastaigny letter of introduction for Professor Dexter? Answer quick.

“Augustus S. F. X. Van Dusen.”

As Professor Dexter glanced at the dispatch his eyes opened a little.

“You don’t believe that Mme. du Chastaigny could have——” he began.

“I daresay I know what Mme. Curie’s answer will be,” interrupted the other abruptly.

“What?”

“It will be no,” was the positive reply. “And then——” He paused.

“Then——?”

“Your veracity may be brought into question.”

With flaming face and tightly clenched teeth but without a word, Professor Dexter saw The Thinking Machine unlock the door and pass out. Then he dropped into a chair and buried his face in his hands. There Mr. Bowen found him a few minutes later.

“Ah, Mr. Bowen,” he said, as he glanced up, “please have this cable sent immediately.”

Once in his apartments The Thinking Machine telephoned to Hutchinson Hatch, reporter, at the office of his newspaper. That long, lean, hungry looking young man was fairly bubbling with suppressed emotion when he rushed into the booth to answer and the exhilaration of pure enthusiasm made his voice vibrant when he spoke. The Thinking Machine readily understood.

“It’s about the radium theft at Yarvard that I wanted to speak to you,” he said.

“Yes,” Hatch replied. “just heard of it this minute—a bulletin from Police Headquarters. I was about to go out on it.”

“Please do something for me first,” requested The Thinking Machine. “Go at once to the Hotel Teutonic and ascertain indisputably for me whether or not Mme. du Chastaigny, who is stopping there, is accompanied by a child.”

“Certainly, of course,” said Hatch, “but the story——”

“This is the story,” interrupted The Thinking Machine, tartly. “If you can learn nothing of any child at the hotel go to the steamer on which she arrived yesterday from Liverpool and inquire there. I must have definite, absolute, indisputable evidence.”

“I’m off,” Hatch responded.

He hung up the receiver and rushed out. He happened to be professionally acquainted with the chief clerk of the Teutonic, a monosyllabic, rotund gentleman who was an occasional source of private information and who spent his life adding up a column of figures.

“Hello, Charlie,” Hatch greeted him. “Mme. du Chastaigny stopping here?”

“Yep,” said Charlie.

“Husband with her?”

“Nope.”

“By herself when she came?”

“Yep.”

“Hasn’t a child with her?”

“Nope.”

“What does she look like?”

“A corker!” said Charlie.

This last loquacious outburst seemed to appease the reporter’s burning thirst for information and he rushed away to the dock where the steamship, Granada from Liverpool, still lay. Aboard he sought out the purser and questioned him along the same lines with the same result. There was no trace of a child. Then Hatch made his way to the home of The Thinking Machine.

“Well?” demanded the scientist.

The reporter shook his head.

“She hasn’t seen or spoken to a child since she left Liverpool so far as I can ascertain,” he declared.

It was not quite surprise, it was rather perturbation in the manner of The Thinking Machine now. It showed in a quick gesture of one hand, in the wrinkles on his brow, in the narrowing down of his eyes. He dropped back into a chair and remained there silent, thoughtful for a long time.

“It couldn’t have been, it couldn’t have been, it couldn’t have been,” the scientist broke out finally.

Having no personal knowledge on the subject, whatever it was, Hatch discreetly remained silent. After a while The Thinking Machine aroused himself with a jerk and related to the reporter the story of the lost radium so far as it was known.

“The letter of introduction from Mme. Curie opened the way for Mme. du Chastaigny,” he explained. “Frankly I believe that letter to be a forgery. I cabled asking Mme. Curie. A ‘No’ from her will mean that my conjecture is correct; a ‘Yes’ will mean—but that is hardly worth considering. The question now is: What method was employed to cause the disappearance of the radium from that room?”

The door opened and Martha appeared. She handed a cablegram to The Thinking Machine and he ripped it open with hurried fingers. He glanced at the sheet once, then arose suddenly after which he sat down again, just as suddenly.

“What is it?” ventured Hatch.

“It’s ‘Yes,’ ” was the reply.

• • • • • •

In the seclusion of his own small laboratory The Thinking Machine was making some sort of chemical experiment about eight o’clock that night. He was just hoisting a graduated glass, containing a purplish, hazy fluid, to get the lamp light through it, when an idea flashed into his mind. He permitted the glass to fall and smash on the floor.

“Perfectly stupid of me,” he grumbled and turning he walked into an adjoining room without so much as a glance at the wrecked glass. A minute later he had Hutchinson Hatch on the telephone.

“Come right up,” he instructed.

There was that in his voice which caused Hatch to jump. He seized his hat and rushed out of his office. When he reached The Thinking Machine’s apartments that gentleman was just emerging from the room where the telephone was.

“I have it,” the scientist told the reporter, forestalling a question. “It’s ridiculously simple. I can’t imagine how I missed it except through stupidity.”

Hatch smiled behind his hand. Certainly stupidity was not to be charged against The Thinking Machine.

“Come in a cab?” asked the scientist.

“Yes, it’s waiting.”

“Come on then.”

They went out together. The scientist gave some instruction to the cabby and they clattered off.

“You’re going to meet a very remarkable person,” The Thinking Machine explained. “He may cause trouble and he may not—any way look out for him. He’s tricky.”

That was all. The cab drew up in front of a large building, evidently a boarding house of the middle class. The Thinking Machine jumped out, Hatch following, and together they ascended the steps. A maid answered the bell.

“Is Mr.—Mr.—oh, what’s his name?” and The Thinking Machine snapped his fingers as if trying to remember. “Mr——, the small gentleman who arrived from Liverpool yesterday——”

“Oh,” and the maid smiled broadly, “you mean Mr. Berkerstrom?”

“Yes, that’s the name,” exclaimed the scientist. “Is he in, please?”

“I think so, sir,” said the maid, still smiling. “Shall I take your card?”

“No, it isn’t necessary,” replied The Thinking Machine. “We are from the theatre. He is expecting us.”

“Second floor, rear,” said the maid.

They ascended the stairs and paused in front of a door. The Thinking Machine tried it softly. It was unlocked and he pushed it open. A bright light blazed from a gas jet but no person was in sight. As they stood silent, they heard a newspaper rattle and both looked in the direction whence came the sound.

Still no one appeared. The Thinking Machine raised a finger and tiptoed to a large upholstered chair which faced the other way. One slender hand disappeared on the other side to be lifted immediately. Wriggling in his grasp was a man—a toyman—a midget miniature in smoking jacket and slippers who swore fluently in German. Hatch burst out laughing, an uncontrollable fit which left him breathless.

“Mr. Berkerstrom, Mr. Hatch,” said The Thinking Machine gravely. “This is the gentleman, Mr. Hatch, who stole the radium. Before you begin to talk, Mr. Berkerstrom, I will say that Mme. du Chastaigny has been arrested and has confessed.”

“Ach, Gott!” raged the little German. “Let me down, der chair in, ef you blease.”

The Thinking Machine lowered the tiny wriggling figure into the chair while Hatch closed and locked the door. When the reporter came back and looked, laughter was gone. The drawn wrinkled face of the midget, the babyish body, the toy clothing, added to the pitiful helplessness of the little figure. His age might have been fifteen or fifty, his weight was certainly not more than twenty‑five pounds, his height barely thirty inches.

“It iss as we did him in der theatre, und——” Mr. Berkerstrom started to explain limpingly.

“Oh, that was it?” inquired The Thinking Machine curiously as if some question in his own mind had been settled. “What is Mme. du Chastaigny’s correct name?”

“She iss der famous Mlle. Fanchon, und I am der marvellous midget, Count von Fritz,” proclaimed Mr. Berkerstrom proudly in play-bill fashion.

Then a glimmer of what had actually happened flashed through Hatch’s mind; he was staggered by the sublime audacity which made it possible. The Thinking Machine arose and opened a closet door at which he had been staring. From a dark recess he dragged out a suit case and from this in turn a small steel box.

“Ah, here is the radium,” he remarked as he opened the box. “Think of it, Mr. Hatch. An actual value of millions in that small box.”

Hatch was thinking of it, thinking all sorts of things, as he mentally framed an opening paragraph for this whooping big yarn. He was still thinking of it as he and The Thinking Machine accompanied willingly enough by the midget, entered the cab and were driven back to the scientist’s house.

An hour later Mme. du Chastaigny called by request. She imagined her visit had something to do with the purchase of an ounce of radium; Detective Mallory, watching her out a corner of his official eye, imagined she imagined that. The next caller was Professor Dexter. Dumb anger gnawed at his heart, but he had heeded a telephone request. The Thinking Machine and Hatch completed the party.

“Now, Mme. du Chastaigny, please,” The Thinking Machine began quietly, “will you please inform me if you have another ounce of radium in addition to that you stole from the Yarvard laboratory?”

Mme. du Chastaigny leaped to her feet. The Thinking Machine was staring upward with squint eyes and finger tips pressed together. He didn’t alter his position in the slightest at her sudden move—but Detective Mallory did.

“Stole?” exclaimed Mme. du Chastaigny. “Stole?”

“That’s the word I used,” said The Thinking Machine almost pleasantly.

Into the woman’s eyes there leapt a blaze of tigerish ferocity. Her face flushed, then the colour fled and she sat down again, perfectly pallid.

“Count von Fritz has recounted his part in the affair to me,” went on The Thinking Machine. He leaned forward and took a package from the table. “Here is the radium. Now have you any radium in addition to this?”

“The radium!” gasped the Professor incredulously.

“If there is no denial Count von Fritz might as well come in, Mr. Hatch,” remarked The Thinking Machine.

Hatch opened the door. The midget bounded into the room in true theatric style.

“Is it enough, Mlle. Fanchon?” inquired the scientist. There was an ironic touch in his voice.

Mme. du Chastaigny nodded, dumbly.

“It would interest you, of course, to know how it came out,” went on The Thinking Machine. “I daresay your inspiration for the theft came from a newspaper article, therefore you probably know that I was directly interested in the experiments planned. I visited the laboratory immediately after you left with the radium. Professor Dexter told me your story. It was clever, clever, but there was too much radium, therefore unbelievable. If not true, then why had you been there? The answer is obvious.

“Neither you or anyone else save Mr. Dexter entered that laboratory. Yet the radium was gone. How? My first impression was that your part in the theft had been to detain Mr. Dexter while someone entered the laboratory or else fished out the radium through a window in the glass roof by some ingenious contrivance. I questioned Mr. Dexter as to your precise acts, and ventured the opinion that you had either sneezed or coughed. You had coughed twice—obviously a signal—thus that view was strengthened.

“Next, I examined window and roof fastenings—all were locked. I tapped over the glass to see if they had been tampered with. They had not. Apparently the radium had not gone through the reception room; certainly it had not gone any other way—yet it was gone. It was a nice problem until I recalled that Mr. Dexter had mentioned a suit case. Why did a woman, on business, go out carrying a suit case? Or why, granting that she had a good reason for it, should she take the trouble to drag it into the reception room instead of leaving it in the carriage?

“Now, I didn’t believe you had any radium; I knew you had signalled to the real thief by coughing. Therefore I was prepared to believe that the suit case was the solution of the theft. How? Obviously, something concealed in it. What? A monkey? I dismissed that because the thief must have had the reasoning instinct. If not a monkey then what? A child? That seemed more probable, yet it was improbable. I proceeded, however, on the hypothesis that a child carefully instructed had been the actual thief.”

Open eyes were opened wider. Mme. du Chastaigny, being chiefly concerned, followed the plain, cold reasoning as if fascinated. Count von Fritz straightened his necktie and smiled.

“I sent a cable to Mme. Curie asking if the letter of introduction was genuine, and sent Mr. Hatch to get a trace of a child. He informed me that there was no child just about the time I heard from Mme. Curie that the letter was genuine. The problem immediately went back to the starting point. Time after time I reasoned it out, always the same way—finally the solution came. If not a monkey or a child then what? A midget. Of course it was stupid of me not to have seen that possibility at first.

“Then there remained only the task of finding him. He probably came on the same boat with the woman, and I saw a plan to find him. It was through the driver of the carriage which Mme. du Chastaigny used. I got his number by ’phone at the Hotel Teutonic. Where had Mme. du Chastaigny left a suit case? He gave me an address. I went there.

“I won’t attempt to explain how this woman obtained the letter from Mme. Curie. I will only say that a woman who undertakes to sell an ounce of radium to a man from whom she intends to steal it is clever enough to do anything. I may add that she and the midget are theatrical people, and that the idea of a person in a suit case came from some part of their stage performance. Of course the suit case is so built that the midget could open and close it from inside.”

“Und it always gets der laugh,” interposed the midget, complacently.

After awhile the prisoners were led away. Count von Fritz escaped three times the first day by the simple method of wriggling between the bars of his cell.