American Murder Mysteries: 60 Thrillers & Detective Stories in One Collection. Arthur B. Reeve
"It isn't necessary to go into the theory of the instrument. But the most minute difference of potential between the two masses of mercury will cause the fine point at the junction of the liquids to move up and down.
"Connected to the aerial and the earth, with a crystal detector in series, it is only a matter of applying an ordinary photo-recording drum, and the machine is made."
He had been setting up a light-tight box, inside of which was a little electric lamp. Opposite was a drum covered with bromide paper. He started the clockwork going and after a few moments' careful observation, we went away, and left the thing, trusting that no one was the wiser.
Nothing further occurred that day, except for frequent reports from Burke, who told us how his men were getting on in their shadowing of Forsythe & Co. Apparently, the death of Leon had put a stop to revolutionary plots, or at least had caused the plotters to change their methods radically.
The time was shortening, too, during which Burke could keep the passengers of the Haytien under such close surveillance, and it was finally decided that on the next morning they should be released, while all those suspected were to be shadowed separately by Secret Service agents, in the hope that once free they would commit some overt act that might lead to a clew.
Chapter XXXIII
The Respiration Calorimeter
It was early the next morning, about half an hour after the time set for the release of the passengers, that our laboratory door was flung open and Collette Aux Cayes rushed in, wildly excited.
"What's the matter?" asked Kennedy anxiously.
"Someone has been trying to keep me on the boat," she panted. "And all the way over here a man has been following me."
Kennedy looked at her a minute calmly. We could understand why she might have been shadowed, though it must have been a bungling job of Burke's operative. But who could have wanted her kept on the boat?
"I don't know," she replied, in answer to Kennedy's question. "But somehow I was the only one not told that we could go. And when I did go, one of the Secret Service men stopped me."
"Are you sure it was a Secret Service man?"
"He said he was."
"Yes, but if he had been, he would not have done that, nor let you get away, if he had. Can't you imagine anyone who might want you detained longer?"
She looked at us, half frightened. "N—not unless it is that man—or the woman with him," she replied, clasping her hands.
"You mean Castine?"
"Yes," she replied, avoiding the use of his name. "Ever since you had the body removed, he has been in great fear. I have heard him ask fifty times, 'Where have they taken him?' and 'Is he to be embalmed?'"
"That's strange," remarked Kennedy. "Why that anxiety from him? I remember that it was he who wanted the body left alone. Is it for fear that we might discover something which might be covered up?"
Kennedy disappeared into the anteroom and I heard him making a great fuss as he regulated the various pieces of machinery that surrounded the little chamber.
Some minutes later, he emerged.
"Meet us here in an hour," he directed Collette, "with your guardian."
Quickly Craig telephoned for a tank of oxygen to be sent over to the laboratory, then got Burke on the wire and asked him to meet us down at the dock.
We arrived first and Craig hurried into the lumber-room, where fortunately he found everything undisturbed. He tore off the strip of paper from the drum and held it up. On it was a series of marks, which looked like dots and dashes, of a peculiar kind, along a sort of base line. Carefully he ran his eye over the strip. Then he shoved it into his pocket in great excitement.
"Hello," greeted Burke, as he came up puffing from the hurried trip over from the Customs House, where his office was. "What's doing now?"
"A great deal, I think," returned Kennedy. "Can you locate Castine and that woman and come up to the laboratory—right away?"
"I can put my finger on them in five minutes and be there in half an hour," he returned, not pausing to inquire further, for, like me, Burke had learned that Kennedy could not be hurried in any of his revelations.
Together, Craig and I returned to the laboratory to find that Collette Aux Cayes was already there with her guardian, as solicitous as ever for her comfort and breathing fire and slaughter against the miscreants who had tried to detain her, without his knowledge.
Some minutes later Castine and "Madame" Castine arrived. At sight of Collette she seemed both defiant and restless, as though sensing trouble, I thought. Few words were spoken now by anyone, as Burke and I completed the party.
"Will you be so kind as to step into the little anteroom with me?" invited Craig, holding open the door for us.
We entered and he followed; then, as he led the way, stopped before a little glass window in the compartment which I have described. Collette was next to me. I could feel the tenseness of her senses as she gazed through the window at the body on the shelf-like pallet inside.
"What is this thing?" asked Aux Cayes, as Collette drew back, and he caught her by the arm.
For the moment Kennedy said nothing, but opened a carefully sealed door and slid the pallet out, unhinging it, while I saw Castine trembling and actually turning ashen about the lips.
"This," Kennedy replied at length, "is what is known as a respiration calorimeter, which I have had constructed after the ideas of Professors Atwater and Benedict of Wesleyan, with some improvements of my own. It is used, as you may know, in studying food values, both by the government and by other investigators. A man could live in that room for ten or twelve days. My idea, however, was to make use of it for other things than that for which it was intended."
He took a few steps over to the complicated apparatus which had so mystified me, now at rest, as he turned a switch on opening the carefully sealed door.
"It is what is known as a closed circuit calorimeter," he went on. "For instance, through this tube air leaves the chamber. Here is a blower. At this point, the water in the air is absorbed by sulphuric acid. Next the carbon dioxide is absorbed by soda lime. Here a little oxygen is introduced to keep the composition normal and at this point the air is returned to the chamber."
He traced the circuit as he spoke, then paused and remarked, "Thus, you see, it is possible to measure the carbon dioxide and the other respiration products. As for heat, the walls are constructed so that the gain or loss of heat in the chamber is prevented. Heat cannot escape in any other way than that provided for carrying it off and measuring it. Any heat is collected by this stream of water which keeps the temperature constant and in that way we can measure any energy that is given off. The walls are of concentric shells of copper and zinc with two of wood, between which is 'dead air,' an effective heat insulator. In other words," he concluded, "it is like a huge thermos bottle."
It was all very weird and fascinating. But what he could have been doing with a dead body, I could not imagine. Was there some subtle, unknown poison which had hitherto baffled science, but which now he was about to reveal to us?
He seemed to be in no hurry to overcome the psychological effect his words had on his auditors, for as he picked up and glanced at a number of sheets of figures, he went on: "In the case of live persons, there is a food aperture here, a little window with air locks arranged for the passage of food and drink. That large window through which you looked admits light. There is also a telephone. Everything is arranged so that all that enters, no matter how minute, is weighed and measured. The same is true of all that leaves. Nothing is too small to take into account."
He shook the sheaf of papers before us. "Here I have some records which have been made by myself, and, in my absence,