"That's your plaything, Martin. You are to raise or lower us by pressing that key. It controls the donkey engine electrically, so that we guide our own destinies though we are a mile beneath our power plant. Stanley works the pump. I direct the searchlight, write down notes, and, I sincerely hope, take snapshots of deep sea life." For a moment my part of the labor seemed so easy as to be unfair. Merely to sit there and punch a little key at raising and lowering time! But as I thought it over it began to appear more difficult. The _Rosa_ could not anchor, of course, in a mile of water. We would drift helplessly. If we approached an undersea cliff I must raise us at once to prevent us being smashed against it. And if the cliff were too lofty to be cleared in time.... I mentioned this to the Professor. "That would be unfortunate," he said, with his frosty smile. "Stanley assures us this glass is unbreakable. He means commercially unbreakable. What would happen to it if it were submitted to the strain of being flung against a rock pile--in addition to the enormous stress of the water pressure--I don't know. It's your job to see that we don't have to find out!" * * * * * It had been planned to test the sphere empty first to see how it stood the strain. We drifted to a full stop over the center of Penguin Deep where we were to gamble our lives in a game with Neptune. Sea anchors were rigged to lessen our drift and the donkey engine was geared to the first cable drum. There was an impressive row of these drums, each holding an interminable length of three-quarter-inch cable. The bulk of a mile of steel cable has to be seen to be believed! The glass sphere was lifted from the hold, delicately for all its enormous weight, and swung over the rail preparatory to being lowered into the depths. Not until that moment did I notice two things: that there was no fastening of any kind to keep the thick lid in place: and that the three-quarter-inch cable looked like a pack thread in comparison to the ponderous bulk it strained to support. "We couldn't use a heavier cable," said the Professor, "because of the strain. We're overloading the hoist as it is. As for the lid being fastened down--I think you'll find it will be pressed into place securely enough!" There was unanimous silence as the great globe slipped into the sea--down and down until the last reflection of the morning sun ceased to shimmer from its surface. Drum after drum was played out, till the first mate held his hand up to check the engineer. "Five thousand feet, sir," he called to Stanley. "Haul it back up. And let us hope," Stanley added fervently, "that we'll find the gadget in one piece." * * * * * The engine began to snort rhythmically. Dripping, vibrating, the coils of cable began to crawl back in place on the drums. There was a glint under the surface again as the sunlight reflected on the nearing sphere.