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.Iwas 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 Iplace 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 moment, Professor Poissan," interrupted Craig; "let your assistant break them out while I stand over him.""Impossible.You would not know when you saw them.They are just rough stones.""Oh, yes, I would."
"No, stay where you are.Unless I attend to it the diamonds might be ruined."There was something peculiar about his insistence, but after he picked out the next diamond I was hardly prepared for Kennedy's next remark.
"Let me see the palms of your hands."
Poissan shot an angry glance at Kennedy, but he did not open his hands.
