that resembled eyes and a
mouth: these were the lookout windows for the under-water observer and
the submarine searchlight.

The _Argonaut_ was built to run on the surface or on the bottom; she was
not designed to navigate half-way between. When in search of a wreck or
made ready for a cruise along the bottom, the trap door or hatch in her
turret-like pilot house was tightly closed; the water was let into her
ballast tanks, and two heavy weights to which were attached strong
cables that could be wound or unwound from the inside were lowered from
their recesses in the fore and after part of the keel of the boat to the
bottom; then the motor was started connected to the winding mechanism,
and, the buoyancy of the boat being greatly reduced, she was drawn to
the bottom by the winding of the anchor cables. As she sank, more and
more water was taken into her tanks until she weighed slightly more than
the water she displaced. When her wheels rested on the bottom her
anchor-weights were pulled completely into their wells, so that they
would not interfere with her movements.

Then the strange submarine vehicle began her voyage on the bottom of
the bay or ocean. Since the pipes projected above the surface plenty of
fresh air was admitted, and it was quite as easy to run the gasoline
engine under water as on the surface. In the turrets, as far removed as
possible from the magnetic influences of the steel hull, the compass was
placed, and an ingeniously arranged mirror reflected its readings down
below where the steersman could see it conveniently. Aft of the
steering-wheel was the gasoline motor, connected with the
propeller-shaft and also with the driving-wheels; it was so arranged
that either could be thrown out of gear or both operated at once. She
was equipped with depth-gauges showing the distance below the surface,
and another device showing the trim of the vessel; compressed-air tanks,
propelling and pumping machinery, an air-compressor and dynamo which
supplied the current to light the ship and also for the searchlight
which illuminated the under-water pathway--all this apparatus left but
little room in the hold, but it was all so carefully planned that not an
inch was wasted, and space was still left for her crew of three or four
to work, eat, and even sleep, below the waves.

Forward of the main space of the boat were the diving and lookout
compartments, which really were the most important parts of the boat, as
far