The Saint Paul globe. (St. Paul, Minn.) 1896-1905, 1898-11-20
Wave propelled Boats.
An Inventor in Italy Partly Solves the Problem \

What aerial navigation is to the in
land aspirant for inventive honors, the
problem of continuing a boat which
shall go against wind and wave, pro-
PEELED by the power of the waves
Which oppose it. is to the seafaring III
ventor. In every seaport town one can
flnG arcient mariners who have been
| working for years along all sorts of
lines to this end and are convinced
thoroughly Of the ultimate practicable
ity Of their plans. The fact that several
OF their predecessors occupy places in
the local cemeteries as a result of too
great zeal in experimentation with
boats of this type doesn't seem to have
& deterrent effect upon the rest, who
go on from failure to failure with un-
diminished courage
And now comes the news from Italy
that their project is not visionary; that
boat has actually been built and
operated which navigateS against the
waves or in any direction counter to
them or equally we'll with them by no
other force than that derived from the
waves themselves. In the last Issue of
the Scientific American this craft is de-
soribed In detail.
The wave-propelled boat is 1912 feet
long, 3.12 feet beam, 1.64 feet in de . h
and has displacement of about 440
pounds. 1t is decked over, except for
a small cockpit in the middle for the
steersman, and has water-tight COM
partments at both ends. Tho little craft
is stanchly enough made 10 stand heavy
weather at sea- She is the invention of
Fl. F. L. Linden, secretary of the ZOO
logical station at Naples, Italy, where
the experiments have been made. The
motor contrivance consists in a series
of powerful resilient floats with free
ends, attached to the boat at bow and
stern, Each float is Of four hardened
n = ~ q
inches in breadth and .06S inch in thick
ness at the attached ends. thinning out
to .0098 inch at the free ends. Canvas is
spread between the plates. giving all
area on the upper surface OF each hoat
Of about 131a square feet. In some cases
the inventor has increased the resili-
eucy Of the floats by means of steel
tongues. The floats are placed at such
a depth that they shall at all times be
under water.
The principle upon which the boat
proceeds is that of the swimming mo-
ton of fishes, which the invetor has
had plenty Of opportunity Of observing
in his duties at the Geological gardens.
He made up his mind that the swim
ming motion of the fishes which he
studied might be initiated mechanical
ly with good results, and his expert
ments finally crystallized in the dis
covery Of the following facts given in
his own words:
IF powerful. resilient floats be at
tached horizantally, obliquely or verti-
cally under the water line Of floating
body, for example a boat, in such
manner that the free ends of the floats
(made of sheet steel or Of other elastic
material, or of some skeleton covered
by q membrance like the webbed feet
of aquatic birds) are directed rear
wardIy, then the boat will move con
stantly and spontaneously onward
through the waves, by reason Of the
impact of the water on the elastic
floats. the operation of the latter cor
responding essentially to the action of
a fish's tall
THE resistance encountered in the
water by the floats, due either to the
motion produced by the pitching and
rolling of the boat or to the direct pres
sure produced by the impact Of masses
Of water falling on the upper surfaces
of the floats. causes these elastic
floats to bend outwardly to a CORE
spending degree; but as soon as the
waves have momentarily subsidized the
floats spring back to their initial posi-
ton It is evident that the striking of
the masses of water against the arched
surfaces of the floats, as well as the
exertion of force during the backward
springing, gives rise to a force which
is directed toward the fast ends of the
floats and which drives the boat in the
direction Of this impulse. Thus, by
means Of a continuous motion Of al
tentative arching and backward
springing the boat is put in motion,
and as already remarked. in direc-
ton from the free to the fast end of
the floats
THE effect of the floats IS the more
pronounced as the motion Of the waves
is stronger and more frequent. Owing
to the resistance encountered by the
floats in the water. the pitching and
rolling of the boat are materially re-
duced."
After experimenting with the floats
in various positions and on various