In silence, for a minute or more, he studied the unconcealed skepticism in his employer's face, and then asked slowly: "Do you know what diamonds are, Mr.Latham ?" "There is some theory that they are pure carbon, crystallized." "They are that," declared the expert impatiently.

"You know that diamonds have been made ?" "Oh, I've read something about it, yes; but what I--" "Every school-boy knows how to make a diamond, Mr.Latham.

If pure carbon is heated to approximately five thousand degrees Fahrenheit, and simultaneously subjected to a pressure of approximately six thousand tons to the square inch, it becomes a diamond.

And there's no theory about that--that's a fact! The difficulty has always been to apply the knowledge we have in a commercially practicable way--in other words, to isolate a carbon that is absolutely pure, and invent a method of applying the heat and pressure simultaneously.

It has been done, Mr.Latham; _it has been done!_ Don't you understand what it means to--" With an effort he repressed the returning excitement which found vent in a rising voice and quick, nervous gestures of the hands.