el engines flung into the gearing. At our
highest speed we now went rushing toward the free Atlantic.[6]

[Footnote 6: (C)]

The homeward voyage was completed without untoward incident and long
before the month had ended, the first--and probably last--merchant
submarine was again safe and snug in her home port.

The cargo-carrying submarine, however, is by no means the only type
of underwater vessel engaged in peaceful pursuits which has been
suggested so far. Mr. Simon Lake, the American submarine engineer
and inventor, has frequently pointed out the commercial
possibilities of the submarine.

In the early part of 1916 a series of articles from his pen appeared
in _International Marine Engineering_. They contained a number of
apparently feasible suggestions looking towards the commercial
development of the submarine.

First of all he tells of experiments made with submarines for
navigation under ice. The proper development of this idea, of
course, would be of immense commercial value. Many harbours in
various parts of the world are inaccessible during the winter months
for vessels navigating on the surface. Navigation on many important
inland lakes likewise has to be stopped during that period.
Submarines, built so that they can safely travel under the ice,
would overcome these conditions and would make it possible to use
most ice-bound ports throughout the entire year at least in Mr.
Lake's view.

Ever since Mr. Lake began inventing and building submarines he has
been interested in the possibilities which submarines offer for the
exploration of the sea-bottom and for the discovery of wrecks and
recovery of their valuable cargoes. His first boat, the _Argonaut_,
as we have heard, possessed a diving chamber for just such purposes.
He has continued his investigations and experiments along this line,
and in these articles he shows illustrations of submarine boats and
devices adapted for such work. Properly financed and directed, the
recovery of cargoes from wrecks undoubtedly would not only bring
large financial returns to the backers of such a venture, but also
do away with the immense waste which the total loss of sunken
vessels and cargoes inflicts now on the world. Submarines in peace
may yet recover for the use of man much of the wealth which
submarines in war have sent to the bottom of the sea. Marine
insurance, too, would be favourably affected by such an undertaking.

Still one other commer