an alibi, in order to lead them away from there and gain time, at least, to give Mr. Wynne an opportunity of hiding the other diamonds, if they were there.  He understood what I was trying to do, and fell in with the plan.  He knew that I knew the diamonds were made.  Mr. Birnes doesn’t know; no one knows but you and me and Mr. Wynne, and perhaps the girl!  But, don’t you see, if you don’t accept the proposition he made the diamond market of the world is ruined?  You are ruined!”

“But how do you know they are made?” insisted Mr. Latham doggedly.  “You’ve never seen them made, have you?”

“Mein Gott, Laadham, how do you know when you haf der boil on der pack of your neck?  You can’d zee him, ain’d id?” Mr. Schultze turned to Mr. Czenki.  “Der dhree of us vill go und zee Mr. Wynne.  Id iss der miracle!  Vass iss, iss, und id don’d do any good to say id ain’d.”

CHAPTER XVII

THE GREAT CUBE

A cube of solid, polished steel, some twenty feet square, set on a spreading base of concrete, and divided perpendicularly down the middle into Titanic halves, these being snugly fitted one to the other by a series of triangular corrugations, a variation of the familiar tongue and groove.  Interlacing the ponderous mass, from corner to corner, were huge steel bolts, and the hulking heads of more bolts, some forty on each of the four sides, showed that the whole might be split into halves at will, and readily made whole again, one enormous side sliding back and forth on a short track.

In the two undivided faces of the cube, relatively squaring the center, were four borings somewhat smaller in diameter than an ordinary pencil, and extending through; and directly in the center was focused a network of insulated wires which dropped down out of the gloom overhead.  In the other two sides of the great cube, just where the dividing lines of the halves came, were the funnel-like mouths of a two-inch boring.  This, too, extended straight through.

Directly opposite each of the two mouths, a dozen feet away, was mounted a peculiarly-constructed heavy gun of the naval type.  In a general sort of way these were not unlike twelve-inch ordnance, but the breech was much larger in proportion, the barrel longer, and the bore only two instead of twelve inches.  The mountings were high, and the adjustment so delicate that, looking into the open breech of one gun, the bore through the twenty-foot cube and through the barrel of the gun on the other side seemed to be continuous.