ed me to apply to the _Argonaut_ a further
improvement for which I had already applied for a patent. This
was, doubled around the usual pressure resisting body of a
submarine, a ship-shape form of light plating which would give
greater seaworthiness, better surface speed, and make the vessel
more habitable for surface navigation. It would, in other words,
make a "sea-going submarine," which the usual form of
cigar-shaped vessel was not, as it would not have sufficient
surface buoyancy to enable it to rise with the seas and the seas
would sweep over it as they would sweep over a partly submerged
rock.

The _Argonaut_ was, therefore, taken to Brooklyn, twenty feet
added to her length, and a light water-tight buoyancy
superstructure of ship-shape form added. This superstructure was
opened to the sea when it was desired to submerge the vessel,
and water was permitted to enter the space between the light
plating of the ship-shaped form and the heavy plating of the
pressure resisting hull. This equalized pressure on the light
plates and prevented their becoming deformed due to pressure. The
superstructure increased her reserve of buoyancy in the surface
cruising condition from about 10 per cent. to over 40 per cent.
and lifted right up to the seas like any ordinary type of surface
vessel, instead of being buried by them in rough weather.

This feature of construction has been adopted by the Germans,
Italians, Russians, and in all the latest types of French boats.
It is the principal feature which distinguishes them in their
surface appearance from the earlier cigar-shaped boats of the
diving type. This ship-shaped form of hull is only suited to the
level keel submergence.

In those days submarine boats were a much more unusual sight than
they are to-day and simple fishermen who had never read or heard
about submarines undoubtedly experienced disturbing sensations when
they ran across their first underwater boat. Mr. Lake, a short time
ago, while addressing a meeting of electrical engineers in Brooklyn,
told the following experience which he had on one of his trips in
the _Argonaut_:

On the first trip down the Chesapeake Bay, we had been running
along in forty feet of water and had been down about four hours.
Night was coming on, so we decided to come up to find out wh