"Look at these two dials; they will tell you," replied the professor. "This dial," tapping one with his finger, "indicates the weight of the ship, or the pressure with which she bears upon the ground. This one," indicating the other, "shows the pressure of air inside the hull of the ship. The first, as you see, shows that the ship is now pressing upon the ground with a force of less than a single ton--in other words, she now weighs less than one ton. The air-gauge shows that there is still an air pressure of six pounds per square inch inside the hull, and we therefore have, as I expected we should, a large margin of buoyancy. Now, lieutenant, do me the favour to turn on the vapour once more, very cautiously. Steady! _Stop_! There, Sir Reginald, the index has reached zero, and your ship is now as nearly as possible without weight; and if a man were now underneath her, he might, notwithstanding her gigantic proportions, easily raise her upon his shoulders. Now comes the delicate part of our operation. To your stations on the deck quickly, gentlemen, if you please." The professor's companions, just a trifle excited, perhaps, hurried away to their posts, and the scientist was left alone. The circular windows in the sides of the pilothouse were all left open, and in through them presently floated the voice of the lieutenant shouting: "All ready abaft, professor." "All ready at this end," replied the colonel. The professor reversed the engines, turned on the vapour _very_ cautiously indeed, and simultaneously, with the engines below only just barely moving, the huge propeller began to whirl round at a speed of some sixty revolutions a minute. A breathless pause of perhaps two seconds followed, and then the professor, his forehead damp with nervous perspiration, heard: "Hurrah! She's away!" from the lieutenant. "She moves; she moves!" from the colonel. And, "By Jove, she is actually moving!" from the baronet. Slowly but surely the _Flying Fish_ backed out of the building-shed, until nearly half her immense length projected beyond the walls. Then the voice of the baronet was heard exclaiming: "Ho! stop her! The electric lamp will not clear the roof, I am afraid. Can you give us a little light on the subject, professor?" By way of reply the professor pressed a knob, and the lamp itself flashed its dazzling light upon the scene, when it became apparent that the ship had gradually risen from the ground, bringing the top of her lamp just above the level of the last tie-rod of the roof. "Can you drop her a little? Six inches will do it," said the baronet. The professor opened the air-valve and the ship at once began to settle down. "So! That will do; all clear. You may go astern again now as fast as you please," said the baronet. Once more the great propeller began to revolve, and presently the baronet, from his position under the foremost end of the pilot-house, remarked: