The St. Mary banner. (Franklin, Parish of St. Mary, La.) 1889-1931, 1908-05-09


To those who go down to the ses
in ships probably no discovery in re
cent times has been of m9Se import
ance or tends more to save life thar
that of the possibility OF signalling
from ship to ship and from ship tt
shore by sound. 1t literally, wher
fully developed, will enable steamer!
to hear" their way under all condi
tions of weather and particularly IL
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 o.
every civilized country.
Every one who has made the triI
to Margate. returning after dark
must have been struck by the easy
way in which the steamer seems te
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 ship on clear nights
sound signals will be to her in foggy
ana dirty weather.
The whole apparatus hinges upon
the fact which has been known for 4
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 a
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 APP
paratus consists of microphone,
modification of what we use every
time we speak to the telephone, en-
closed in q 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 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-
scribed above, which are rung at GER
tain intervals, each lighthouse having
. different number Of beats, SO that
any particular lighthouse is distin-
guished by its bell, just as in clear
weather 1t is distinguished by the ar
of its lights. An ap-
preaching ship can tell within a very
close approximation, as mathema-
ticians would say, how it lies with re-
gard to the lighthouse, because the
bell will be heard loudest in that mi
:rophone on the side Of the ship on
which the lighthouse is, and the
'fiacer Of the watch can steer accord
ngly.
Similarly, even with present appli-
lnces. the direction of an approach
ng steamer can be heard in the same
manner. II the approaching ship is
crossed from right to left. or as sea-
men express it. from starboard to
'ort. the noise Of her screw will be
heard more clearly in the microphone
attached to the right hand. or star
'oard. side Of the ship than in that |
n the other side, and 30 a valuable J