"There is nothing more down here. We will now proceed on board, if you please, gentlemen," said the professor; and he forthwith led the way up a ladder which leaned against the vessel's lofty side. This conducted them as far as the upper curve of her cylindrical bilge, at which point they encountered a flight of light ornamental openwork steps permanently attached to the ship's side, up which they passed to the gangway in the stout metal railing which served instead of bulwark, and so reached the spacious promenade deck. Looking down into the yard from this coign of vantage, they seemed to be an enormous height from the ground; and the baronet shrugged his shoulders more expressively than ever as he glanced first below and then around him, realising more fully than ever, as he did so, the immense proportions of his new possession. He said nothing, however, but turned inquiringly to the professor. "This way, gentlemen, if you please," said the German, in answer to the look; and he led them aft to what may be styled the quarter-deck. "You spoke about the weight of a coat of paint on the hull just now, but I see you have planked the deck. The weight of all this planking must be something considerable," remarked Mildmay. "A mere trifle; it is only a thin veneering just to give a secure and comfortable foothold," remarked the professor. He paused at what looked like a trap-door in the deck and said: "We shall not be always soaring in the air nor groping about at the bottom of the sea; we shall sometimes be riding on the surface; and I have therefore thought it advisable to provide a couple of boats. Here is one of them." He stooped down, seized hold of and turned a ring in the flap, and raised the trap-door, disclosing a dark pit-like recess of considerable dimensions. Letting the flap fold back flat on the deck, the professor then stooped down and grasped the handle of a horizontal lever which lay just below the level of the deck, and drew it up into a perpendicular position, and, as he did so, a pair of davits, the upper portions of which had been plainly visible, rose through the aperture close to the protecting railing, bringing with them a handsomely modelled boat hanging from the tackles. The professor deftly turned the davits outward, and there hung the boat at the quarter in the exact position she would have occupied in an ordinary ship. "Bravo, professor; very clever indeed!" exclaimed Mildmay. "But what is the object of those four curved tubes projecting through the boat's bottom?"