The morning news. [volume] (Savannah, Ga.) 1887-1900, 1898-10-16
TO PREVENT COLLISIONS.
SOME INGENIOUS DEVICES FOR
WARNING VESSELS.

ThermOpiIe and Its Sensitive Oper-
atiOn-PrOf. oliver Lodges Plan
for DispeIIing Fog by Electricity.
1t is not likely that an accident like that
which sent the Bou-sogne to the bottom
| of the Atlantic win again occur. That
tragic event has reawakened the construc-
tive genius of inventors an over the coun-
try, and as a result the patent office in
! Washington has been overrun with appli-
cants for patents on devices for preventing
| collisions at sea. Some of these devices
are highly ingenious; others are highly
absurd. Nearly every principle of physics,
| optics, acoustics and other kindred sciences
has been called into play by these invent
ors, with the result that we now have sig
mailing instruments which depend on the
sharpness of human hearing or eyesight,
on steam heat, electricity. fire, in short,
on everything which may be utilized as
force. Even fog is to be dissipated by
means of electric influence machines and
at the instance of no less a parsonage than
Prof. Oliver Lodge of Liverpool univer-
sity
The most promising inventions depart
in use. In other words mariners heretofore
have depended on sound as a means of
| signaling to avoid collisions. But the aber-
! rations in the course of sound waves en-
| countered at sea are SO great that this
means is not 10 be depended upon. The
sound waves from a fog horn in a light
house, for instance. may often be heard
a mile and a half distant; then they may
| die away until they are inaudb9e at the
| distance of a mile; afterwards they may
| be heard plainly again at two miles. The
| sound in falling upon the water at an an
! gle seems 20 bound into the air and then
to fatl on the water further on, after which
! il may rebound. This action, however, is
| by no means regular. The inaudible belts
| are sonetimesc wide; somtimes very mar
| row. Therefore while we have the siren,
the eophone, the topophone and other pho
netic contrivances their scope is limited
because of the inability to control the
sound after it has left the instrument. OF
these various phones now in use the pneu-
| matte foghorn is perhaps the best. 1t is
| operated by compressed air. The horn has
| two or more horizontal tunnels, which re-
volve constantly on a pivot. thus endeavor-
| ing to send a prolonged blast to all points
| of the compass.
| Some years ago Edison proposed to use
| compressed air on vessels as a means of
| signaling and avoiding collisions. He pro-
| posed to overcome the difficulty of the I'M
| even alterations by transmitting sound
under water. His scheme would make 1t
necessary for every ship on the ocean to
be fitted out with a separate apparatus
for this purpose. The plan was to con-
struct in the end of each vess6el a dia-
phragm. Back of the diaphragm was to
be a hollow chamber connected by valve
with a compressed air pump. The COM
pressed air was to be used periodically to
inf at n no n NH
causing 1t to sound a note under water
Water is very good conductor of SOUND
Sound will travel for miles beneath the
surface, and it could be received and re-
corded on instruments in the hulls of YES
sells near to the ship from which it came
The plan at least seems to be feasible, and
it has the double advantage Of denoting
the approach of vessels one to another,
and of enabling them to signal necessary
information by means of a modified sys-
tenn of dots and dashes of sound.
The most promising results in the way
of signaling at sea seem to arise out of
the elestrical manipulation of heat. BY
means of themopiles it is now possible TO
record the approach of one vessel toward
another by the heat which the newcomer
transmits through the atmosphere. When
the climatic conditions of the ocean are
taken into consideration il may seem more
than marvellous that any instrument could
be constructed that would be influenced
by the heat of an approaching vessel while
the latter was yet out of human sight
and hearing. If we turn to our physics"
however, we shall find that Ganot de-
scribes a delicate termopile which was
sensbly affected by the heat of a candle
a quarter of a mile away. Another instru-
ment became affected by a heated penny
held twenty feet away. Now, when these
are compared to the general heat develop
ed in the galley or, to go farther, in the
boilers of an ocean vessel, the matter of
transmitting that heat through the atmos-
phere seems not so wonderful after ALL
Herman Herberts of Newark, N. j.. has
constructed an instrument buiIt on the
principle of the thermopile which is in
tended for use on shipboard. 1t is so sensi-
tive that il will detect differences in tenn
perature as slight as one-millionth of de-
gress sentigrade.
1t may be well to state at first how a
thermopile acts. Suppose we take two
pieces of copper wire and secure each
piece to the binding posts of an electric
measuring instrument or galvanometer
We will have naturally two free ends of
copper wire dangling from the galvano-
meter. If now we hold one of the wire
ends in a candle fame and when It is not
press it hard against the remaining wire
which has not been heated we will find
that an electric current will be generated
which will be recorded on the galvano-
T.
man silver and the other is copper we
will find the effect to be very much in
creased That is, a stronger current will
flow, or the same current as before car
be generated with less heat than was used
when both wires were of copper Yet
there are metals or substances which win
be powerfully affected by much less heat
than is necessary with the combination
of German silver and copper. Bismuth
and anumony are very sensitive. Sc
ienium is so extremely sensitive that it's
conductivity is seriously affected even
by varying degrees Of light. There are
other substances quite as easily inhu-
enced. A combination of these Is used
in the Herberts thermopile. Not only
viii it record the approach of a mass Of
heat. but IL will also herald the ap-
proach Of mass Of cold. Therefore it
viii be as useful in denotng the prox-
unity of an iceburg as in telling Of the
approach Of a ship. It will also indicate
the direction from which either heat or
cold is approaching.
Two thermopiles are placed within a
.asa on each side of the vessel Thaaa