“Maybe this man has done it,” agreed Andrews. “Who knows? I’ll wager that if he has and that if Morowitch had bought an interest in his process Kahan knew of it. He’s a sharp one. And Mrs. Morowitch doesn’t let grass grow under her feet, when it comes to seeing the main chance as to money. Now just supposing Mr. Morowitch had bought an interest in a secret like that and supposing Kahan was in love with Mrs. Morowitch and that they—”
“Let us suppose nothing, Mr. Andrews,” interrupted Kennedy. “At least not yet. Let me see; it is now ten minutes after eight. Poissan’s place is only a few blocks from here. I’d like to get there a few minutes early. Let’s start.”
As we left the office, Andrews signalled to the two men outside, and they quietly followed a few feet in the rear, but without seeming to be with us.
Poissan’s laboratory was at the top of a sort of loft building a dozen stories or so high. It was a peculiar building, with several entrances besides a freight elevator at the rear and fire-escapes that led to adjoining lower roofs.
We stopped around the corner in the shadow, and Kennedy and Andrews talked earnestly. As near as I could make out Kennedy was insisting that it would be best for Andrews and his men not to enter the building at all, but wait downstairs while he and I went up. At last the arrangement was agreed on.
“Here,” said Kennedy, undoing a package he had carried, “is a little electric bell with a couple of fresh dry batteries attached to it, and wires that will reach at least four hundred feet. You and the men wait in the shadow here by this side entrance for five minutes after Jameson and I go up. Then you must engage the night watchman in some way. While he is away you will find two wires dangling down the elevator shaft. Attach them to these wires from the bell and the batteries—these two—you know how to do that. The wires will be hanging in the third shaft—only one elevator is running at night, the first. The moment you hear the bell begin to ring; jump into the elevator and come up to the twelfth floor—we’ll need you.”
As Kennedy and I rode up in the elevator I could not help thinking what an ideal place a down-town office building is for committing a crime, even at this early hour of the evening. If the streets were deserted, the office-buildings were positively uncanny in their grim, black silence with only here and there a light.
The elevator in the first shaft shot down again to the ground floor, and as it disappeared Kennedy took two spools of wire from his pocket and hastily shoved them through the lattice work the third elevator shaft. They quickly unrolled, and I could hear them strike the top of the empty car below in the basement. That meant that Andrews on the ground floor could reach the wires and attach them to the bell.
Quickly in the darkness Kennedy attached the ends of the wires to the curious little coil I had seen him working on in the laboratory, and we proceeded down the hall to the rooms occupied by Poissan, Kennedy had allowed for the wire to reach from the elevator-shaft up this hall, also, and as he walked he paid it out in such a manner that it fell on the floor close to the wall, where, in the darkness, it would never be noticed or stumbled over.
Around an “L” in the hall I could see a ground-glass window with a light shining through it. Kennedy stopped at the window and quickly placed the little coil on the ledge, close up against the glass, with the wires running from it down the hall. Then we entered.
“On time to the minute, Professor,” exclaimed Poissan, snapping his watch. “And this, I presume, is the banker who is interested in my great discovery of making artificial diamonds of any size or colour?” he added, indicating me.
“Yes,” answered Craig, “as I told you, a son of Mr. T. Pierpont Spencer.”
I shook hands with as much dignity as I could assume, for the role of impersonation was a new one to me.
Kennedy carelessly laid his coat and hat on the inside ledge of the ground-glass window, just opposite the spot where he had placed the little coil on the other side of the glass. I noted that the window was simply a large pane of wire-glass set in the wall for the purpose of admitting light in the daytime from the hall outside.
The whole thing seemed eerie to me—especially as Poissan’s assistant was a huge fellow and had an evil look such as I had seen in pictures of the inhabitants of quarters of Paris which one does not frequent except in the company of a safe guide. I was glad Kennedy had brought his revolver, and rather vexed that he had not told me to do likewise. However, I trusted that Craig knew what he was about.
We seated ourselves some distance from a table on which was a huge, plain, oblong contrivance that reminded me of the diagram of a parallelopiped which had caused so much trouble in my solid geometry at college.
“That’s the electric furnace, sir,” said Craig to me with an assumed deference, becoming a college professor explaining things to the son of a great financier. “You see the electrodes at either end? When the current is turned on and led through them into the furnace you can get the most amazing temperatures in the crucible. The most refractory of chemical compounds can be broken up by that heat. What is the highest temperature you have attained, Professor?”
“Something over three thousand degrees Centigrade,” replied Poissan, as he and his assistant busied themselves about the furnace.
We sat watching him in silence.
“Ah, gentlemen, now I am ready,” he exclaimed at length, when everything was arranged to his satisfaction. “You see, here is a lump of sugar carbon—pure amorphous carbon: Diamonds, as you know, are composed of pure carbon crystallised under enormous pressure. Now, my theory is that if we can combine an enormous pressure and an enormous heat we can make diamonds artificially. The problem of pressure is the thing, for here in the furnace we have the necessary heat. It occurred to me that when molten cast iron cools it exerts a tremendous pressure. That pressure is what I use.”
“You know, Spencer, solid iron floats on molten iron like solid water—ice—floats on liquid water,” explained Craig to me.
Poissan nodded. “I take this sugar carbon and place it in this soft iron cup. Then I screw on this cap over the cup, so. Now I place this mass of iron scraps in the crucible of the furnace and start the furnace.”
He turned a switch, and long yellowish-blue sheets of flame spurted out from the electrodes on either side. It was weird, gruesome. One could feel the heat of the tremendous electric discharge.
As I looked at the bluish-yellow flames they gradually changed to a beautiful purple, and a sickish sweet odour filled the room. The furnace roared at first, but as the vapors increased it became a better conductor of the electricity, and the roaring ceased.
In almost no time the mass of iron scraps became molten. Suddenly Poissan plunged the cast-iron cup into the seething mass. The cup floated and quickly began to melt. As it did so he waited attentively until the proper moment. Then with a deft motion he seized the whole thing with a long pair of tongs and plunged it into a vat of running water. A huge cloud of steam filled the room.
I felt a drowsy sensation stealing over me as the sickish sweet smell from the furnace increased. Gripping the chair, I roused myself and watched Poissan attentively. He was working rapidly. As the molten mass cooled and solidified he took it out of the water and laid it on an anvil.
Then his assistant began to hammer it with careful, sharp blows, chipping off the outside.
“You see, we have to get down to the core of carbon gently,” he said, as he picked up the little pieces of iron and threw them into a scrap-box. “First rather brittle cast iron, then hard iron, then iron and carbon, then some black diamonds, and in the very centre the diamonds.
“Ah! we are getting to them. Here is a small diamond. See, Mr. Spencer—gently Francois—we shall come to the large ones presently.”
“One