ttle on the end of a tube; this has
lenses and mirrors that reflect into the interior of the submarine
whatever shows above water. The bottle part projects above, while the
tube penetrates the interior.

[Illustration: SPEEDING AT THE RATE OF 102-3/4 MILES AN HOUR]

The very unexpectedness of the submarine's attack, the mere knowledge
that they are in the vicinity of a fleet and may launch their deadly
missiles at any time, is enough to break down the nerves of the
strongest and eventually throw into a panic the bravest crew.

That the crews of the war-ships will have to undergo the strain of
submarine attack in the next naval war is almost sure. All the great
nations of the world have built fleets of submarines or are preparing to
do so.

In the development of under-water fighting-craft France leads, as she
has the largest fleet and was the first to encourage the designing and
building of them. But it was David Bushnell that invented and built the
first practical working submarine boat, and in point of efficiency and
practical working under service conditions in actual readiness for
hostile action the American boats excel to-day.

A PEACEFUL SUBMARINE

Under the green sea, in the total darkness of the great depths and the
yellowish-green of the shallows of the oceans, with the seaweeds waving
their fronds about their barnacle-encrusted timbers and the creatures of
the deep playing in and about the decks and rotted rigging, lie hundreds
of wrecks. Many a splendid ship with a valuable cargo has gone down off
a dangerous coast; many a hoard of gold or silver, gathered with
infinite pains from the far corners of the earth, lies intact in
decaying strong boxes on the bottom of the sea.

To recover the treasures of the deep, expeditions have been organised,
ships have sailed, divers have descended, and crews have braved great
dangers. Many great wrecking companies have been formed which accomplish
wonders in the saving of wrecked vessels and cargoes. But in certain
places all the time and at others part of the time, wreckers have had to
leave valuable wrecks a prey to the merciless sea because the ocean is
too angry and the waves too high to permit of the safe handling of the
air-hose and life-line of the divers who are depended upon to do all
the under-water work, rigging of hoisting-tackle, placing of buoys, etc.
Indeed, it is often impossible for a vessel to stay in one place long
enough to accomplish anythi