"Once in a while, old dear," replied the Doctor with a chuckle, "which is more than anyone in the Secret Service does. You might tell Bolton that I said that, but hang up quickly if you do. I don't want the wires of my telephone melted off. No, Carnesy, I have no miraculous inspiration as to where that gold is coming from; I just have a plain old-fashioned hunch, and that hunch is that we are going to have lots of fun and more than our share of danger before we see Washington again. After you get through bearding Bolton in his den, you might call the Chief of the Air Corps and ask him to have a bomber held at Langley Field subject to my orders. If he squawks any, I'll talk to him." He turned to a telephone which stood on his desk and lifted the receiver. "Get Mr. Lambertson on the wire," he said. "He is the chief technician of the Pyrex Glass Works at Corning, New Jersey." * * * * * The _U.S.S. Minneconsin_ steamed out of New York harbor and headed down toward the lower bay. On her forward deck rested a huge globe. The bottom quarter of the sphere was made of some dark opaque substance but the upper portion was transparent as crystal. Through the walls could be seen a quantity of apparatus resting on the opaque bottom portion. Two mechanics from the Bureau of Standards were making final adjustments of one of the pieces of apparatus, which resembled a tank fitted with a piston geared to an electric motor. From the tank, tubes ran to four hollow pipes, an inch and a half in diameter, which ran through the skin and extended thirty inches from the outer skin of the twenty-foot sphere. Dr. Bird stood near talking with the executive officer of the ship and from time to time giving a brief word of direction to the mechanics. "It's safer than you might think, Commander," he said. "In the first place, that globe is not made of ordinary glass; it is made of vitrilene, a new semi-malleable glass which was developed at the Bureau and which is being made on an experimental scale for us by the Pyrex people. It is much stronger than ordinary glass, and is not sensitive to shock. It is also perfectly transparent to ultra-violet light, being superior even to rock crystal or fused quartz in that respect. The walls, as you have noticed, are four inches thick, and I have calculated that the ball will stand a uniform external pressure of thirty-five hundred atmospheres, the pressure which would be encountered at a depth of about twenty miles. I believe that it will stand a squeeze of six thousand tons without buckling, and it is impossible to fracture it by shock. It could be dropped from the top of the Woolworth Building, and it would just bounce." "It seems incredible that it could stand such a pressure as you have named." "My figures are conservative ones. Lambertson calculated them even higher, but we allowed for the fact that this is the first large mass of the material to be cast, and lowered them."