Shenandoah herald. [volume] (Woodstock, Va.) 1865-1974, 1897-07-30
BOAT WITH FINS.
Swiftly Propelled by the Action OF the
Wayes-New Motive Force.

Swiftly Propelled by the Action OF the
wayes-Sew Motive Force.
Tourists at Naples this spring have
noticed a little open boat which set out
seward whenever the sea was rough,
and particularly when the treacherous
sirocco sent the turbulent waves spray
ing over the stone coping of the Via
Corraciolo. Once having noticed the
little frail shell, the fact of its going
out in heavy weather seemed so much
more strange since it was impossible to
tell how it moved about. The single
person seated in the boat did not row,
there was no sail, no smokestack was
visible, no wheel, no screw, no boiler,
no engine-none of the metal parts un-
avoidable in motors Of any kind and no
noise indicating any of the ordinary
motive powers which man has made a
tributary. At the rudder the man was
calmly seated directing the little shell
wherever he wanted to 60.
What was driving the little boat
through the turbulent waves? Its in
ventor and constructor, Secretary Lin
den of the geological station at Naples,
kindly explained the simple and exceed
ingly clever invention, which he has
Just patented in several countries and
which is to be introduced both In the
German and Austrian navies. The for
ward and aft ends of the boat are pro-
vided with vertical steel rods. At the
end Of these steel rods, which are dip
ped in the sea, wedge shaped plates Of
spring steel Of great firmness are fas-
tened horizontally with the wide and
thin end away from the boat When
these piiable plates are made to yibrate
by means Of thu movement of the
waves, they act like the fins Of fish
and drive the boat forward. Not the
waves alone furnish the power, for in
perfectly still water the mere pitching
Of the vessel will result in forward
movement. The lowering or raising Of
the steel rods with the fins is an easy
matter, and the fins themselves can be
attached or detached by simple mech
anism in a very few moments.
A trial with the small model of such
boat in one of the basins of the aqua
rum at the station is highly amusing
and surprising at the same time. The
toy is perfectly still when placed in the
water, but as soon as little waves are
produced in the basin with the hand or
small board the toy starts as if driven
by witchcraft The power developed is
rather considerable. and it is best COM
pared with the pull exerted by a kite in
brisk wind. The new boat, which the
inventor has called the AutOnaut is not
exactly boat without a motor, but one
without the ordinary motive powers
as a matter Of fact, the steel fin vibrated
by the motion Of the water is the mo-
tor Of the Autonaut.
Secretary Linden first conceived the
idea Of the new motive force while OBJ
serving the movement Of the fishes in
the aquarium, particularly the tail mo-
tions, the most important apparently in
the locomotion of the fnny tribe. After
many years experiments, calculations
and improvements his last boat, which
is 3 feet long, has recently run against
strong wind and tide in the gulf Of
Naples at the rate Of 3 y miles an hour.
The steel fins were together about ten
square feet in size, and be has by ex-
periments established the best size to
be about one-third Of the surface upon
which the boat is resting. The fins,
which were first made of several layers
Of thin spring steel, are now wrought
out Of one piece, and the most effective
shape is that of the dolphin's tail fin.
The new boat can be steered in the or
binary manner and will draw another
boat heavier than it is itself. The ap-
paratus is cheap and can be supplied to
any boat even if it has other motive
power
No matter how little wind, the tide
movement alone is sufficient to .mpart
enough motion to the waves to propel
the boat provided with Linden fans.
The greatest Gcld Of the Linden boat.
however, and where its value is ines
timable, is in the use Of life saving ap-
paratus which has to travel short dis
tances in almost always heavy weather.
The crew would arrive at the spot
where they are wanted in excellent con-
dition and would be Of much more help
TO a shipwrecked crew than now, when
they arrive after dreadful and often use
less efforts against the overwhelming
odds Of waves and wind combined
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