e
result that the huge craft at once began to settle down toward the
surface of the sea, upon which, a few minutes later, she floated
buoyantly as a soap-bubble. Then the main air-pumps were set to work,
forcing compressed air into the vacuum chambers, and causing the ship to
sink very gradually in the water, while at the same time, to facilitate
the operation of sinking, water was admitted into certain of the ballast
chambers in the ship's bottom until she floated at her ordinary trim for
cruising on the surface of the sea--that is to say, with the whole of
her immense propeller completely submerged, and her conical-pointed bow
buried to the depth of a foot or so. During this operation of
submergence the engines had been stopped, but they were now sent ahead
again at full speed; and some ten minutes later the singular-looking
craft ranged up on the weather quarter of a big black-hulled steamer of
about three thousand tons register, the round stern of which bore the
name of _Ludwig Gadd_ in large, yellow-painted Russian characters. This
alone was sufficient to identify her beyond question as the convict-ship
of which they were in search; but if further evidence had been needed it
was to be found in the "pen"--a stout, substantially built wooden
structure of closely set palings, about ten feet high, that occupied
nearly the whole of the fore-deck, except a narrow alley-way on each
side of it to allow of the passage of the crew fore and aft, and which
included the great main hatchway, the covers of which had been replaced
by a stout grating, with a small aperture in it just large enough for a
man to squeeze through, and at which a soldier with a loaded rifle stood
guard.

There were not many people visible about the convict-ship's decks, for
the hour was still early, and the business of the day had not yet
begun--although, had she been British, her crew would already have been
at the job of washing the decks and scouring the paint and brass-work.
But here a solitary seaman slouched to and fro on the topgallant
forecastle, keeping a perfunctory lookout; two or three others lolled
over the rail forward, staring in stupid, open-mouthed wonderment at the
silver shape of the _Flying Fish_; and the officer of the watch paced
the bridge athwartships with an air of great importance, pausing for a
moment every time he passed the compass, to glance into its bowl, or
murmur a word to quicken the vigilance of the helmsman.

As t