It was a giant glass sphere, polished and flawless. Inside it could be made out various objects—a circular bench arrangement on a wooden flooring, batteries that filled the cup between the floor and the bottom arc of the sphere, tall metal cylinders, a small searchlight set next to a mechanism that was indeterminate. At three equidistant points on the sides there were glass handles, as thick as a man's thigh, cast integral with the walls. On the top there was a smaller handle.
At first glance the sphere seemed all in one piece, with the central objects cast inside like a toy ship in a sealed bottle. Then a mathematically precise ring of prismatic reflections showed me that the top third of the ball was a separate piece, fitting conically down like the tapered glass stopper of a monstrous perfume bottle. The handle on the top was for the purpose of lifting this giant's teapot lid, and allowing entrance into the sphere.
"Isn't it a beauty?" murmured Stanley. "It ought to be," he added. "It cost me eighty-six thousand to make it in my own glass factory. Eleven castings before this one came along that was reasonably free of flaws. Twenty-two feet six inches over all, walls five feet thick, new formula unbreakable glass, four men working a month to grind the lid into place, tolerance limits plus or minus zero."
He slapped the Professor's shoulders. "Let's go in and look over the apparatus."
To accommodate the huge ball a well had been constructed in the Rosa's hold. This brought the deck we were standing on up to within six feet of the top ring, above which was rigged a chain hoist for lifting the ponderous lid.
The hoist was revolved, the conical top was swung free, and we clambered into our unique diving shell.
The tall cylinders were revealed as great flasks of compressed air. The indeterminate thing beside the searchlight turned out to be a hand pump, geared to work against heavy pressure. From the suction chamber of this three tubes extended.
"We inhale the air of the chamber," the Professor explained to me, "and exhale through the tubes into the pump cylinder. Breathe in through the nose and out through the mouth. The pump piston is forced down by this geared handle, sending the used air out of the shell through this sixteenth-inch hole. A ball check valve keeps the water from squirting in when the exhaust pressure is released."
He pointed to a telegraphic key which completed a circuit from the batteries in the bottom of the ball to a thread of copper cast through the lid.