The St. Mary banner. (Franklin, Parish of St. Mary, La.) 1889-1931, 1908-05-02

To those who 60 down to the sea
in ships probably no discovery IN re-
cent times has been Of mc@e import
ance or tends more to save life than
that of the possibility Of signalling
from ship to ship and from ship to
shore by sound. 1t literally, when
fully developed, will enable steamers
to hear" their way under all condi-
lions of weather and particularly in
fog just as well as they see their way
on clear nights by the aid of the
lights that each ship carries and
those distributed around the coast of
every civilized country.
Every one who has made the trip
to Margate, returning after dark,
must have been struck by the easy
way in which the steamer seems to
find her way through what appears to
be a maze Of traffic. guided by the
lights on shore and those carried by
other vessels in the river. What
lights are to a ship on clear nights
sound signals will be to her in foggy
and dirty weather.
The whole apparatus hinges upon
the fact which has been known for a
long time, but has only recently been
practically applied, that water is a
good conductor of sound. The read
lest example of this of which the
writer is aware is to be found usually
at mineral baths. There is nearly al
ways pumping going on in connection
with the baths, but under ordinary
conditions the pump is not heard.
When undressing, for instance, to en-
ter the bath one can very rarely hear
the pump, but Immediately one is in
the bath, ii one places ones head un-
der water, the pump is almost pain
fully evident, and an engineer could
easily count the strokes had he
watch at hand.
For signalling purposes a bell is
employed, immersed some distance
under the water and enclosed in a
chamber, the hammer being worked
by compressed air operated from the
surface. The sound OF the strokes on
the bell is transmitted to a distance
OF several miles, and can be heard by
suitable apparatus. The hearing ap-
paratus consists Of microphone, q
of what we use every
time we speak to the telephone, en-
closed in chamber inside the ship.
and connected with the bridge by
wires In the usual way. The micro
phone is filled with a special liquid
which the inventors have found to
answer the purpose best. and there is,
as at present arranged, one chamber
and one microphone on each bow be-
low the water line. In the chart
house on the bridge is a pair of tele-
phone receivers, similar to those we
put to our ears when we talk through
The telephone on shore, and a switch
the receivers to be connect
ed to either Of the two microphones.
Several of the lighthouses on the
coast OF America, and some, the
writer believes. on that OF the United
are fitted with bells as de-
49, 0SA 0OOVCs WAlVn dIO Iuuk HI Ger.
ain intervals. each lighthouse having
J different number of beats, SO that |
my particular lighthouse is distin-
yuished by its bell. just as in clear
weather It is distinguished by the ar
Of its lights. An ap-
'roaching ship can tell within a very |
lose approximation, as mathema-
tcians would say, how it lies with re-
Iard to the lighthouse. because the
'ell will be heard loudest in that mi
rophone on the side OF the ship on
which the lighthouse is, and the
nicer Of the watch can steer accord /
ngly.
Similarly. even with present appli-
noes. the direction Of an approach
ne steamer can be heard In the same |