The times. [volume] (Washington [D.C.]) 1897-1901, 1901-01-21
BELLS UNDER THE OCEAN
The Successful Test of a New
Maritime Signal System.
An Invention Tried OF the Coast of
Massachusetts - Sounds Distinctly
and One-hnIf to Twelve Miles
Opinions rs to Its Practicability.

by announcing the invention of a system
of signaling under water, which is as in
teresting in its way as MarcOni's wireless
telegraphy, and which has as wide a
range of possibility. The system is based
veying sounds for long distances, as Mar
conf uses ether.
By its use it has already been proven
that a vessel can be warned of her APP
proach to the coast when at least twelve
miles off, in storm or calm, while the ap-
proach of one vessel to another can easily
be detected at the same distance. This
much is beyond question. A number Of
prominent men have seen the system
operated, among them Henry NJ. Whitney,
the wellknown capitalist; Wallace c. sa-
bine, professor of physics at Harvard Uni
versity; Commander Arthur z. Nazro, U.
S N, Inspector OF the Lighthouse district,
embracing the Massachusetts coast; \. p.
Barton, master of the United States
steamship Mayhower, and Capt. Edward
Baker, of the coastwise steamer Fl. f.
Dimock, and all are enthusiastic in their
praise of the new invention.
If the receivers used, which are sus-
pended over the ships side and sub
merged, can be made sufficiently sensitive
to respond to ordinary distant sounds,
such as might be produced by the pro-
peller of submarine vessel, then the
greatest problem of naval warfare of to-
day will be solved. AS yet the sounds
made audible at distance by the use
of these receivers have been only prear-
ranged signals produced by very power
full bells, whose vibrations are produced
by powerful electro magnets. BY the as
sistance of this system one warship can
hear the approach of another in thick
weather or at night and communicate
with each other. Vessels at sea in thick
weather can be made aware each of the
others proximity, and danger of collision
can be avoided. vessel approaching the
coast in fog can pick up the sounds of
the warning signal miles off shore, and by
it. with the aid of new system of de-
filming positions on the chart. which goes
with the system, she can pick out her po-
sition exactly. no matter how long she
may have been running on dead reckon
ing.
The system, il perfected on the lines
laid down by its inventors, VIII revolu-
tionize navigation along the coast. The
air will nc longer be depended on as a
medium for transmitting fog signals
Tricky at best as medium for conveying
sound, the air has failed many time to
carry the sound of a powerful fog trum-
pet hundred yards from shore against a
gale. 1t is further claimed for the in
vention that the water carries sound al
ways in the same manner, as there is no
variation in its density as there is in the
case of tia air.
The system is the invention of a Boston
man, Arthur j. Mundy, working in con-
junction with Prof. Elisha Gray, of tele-
phone fame.
In the summer of 1883 Mr. Mundy when
on vacation. went up the Mississippi
River on steamer from New Orleans to
st. Louis. Residents along the river were
at that time much alarmed over the pos
sibAity of Spanish war vessels attacking
the Gulf coast. Mr.. Mundy's thoughts
were directed by this sentiment toward
devices for safety through signaling in
times of war, and while thinking on the
subject he hit upon the idea of submarine
signaling
He recalled the simple experiment often
made by boys of striking two stones to-
gether under water and hearing the sound
He knew that water was an excellent con-
ductor of sound and he believed some
system could be devised by which ships
could be warned from the land, and by
which also persons on shore could hear
the approach of vessel coming in the
dark when it could not be seen.
Mr.. Mundy is not an electrician, and in
the enthusiasm of his new idea he wrote.
while still on the Mississippi steamer. to
Prof. Gray. an old friend who was in Chi
cago, putting the idea and its possibil-
ties before him. Prof. Gray at once saw
the chance TO develop great invention
and he came to Boston, Joined hands in
the enterprise with Mr. Mundy and to-
gether, in two years of constant work and
experimenting. they have perfected their
system of signaling
One day last week the system was given
its first semi public test, a party OF fifteen
prominent men, representing the United
States Navy, shipping interests. and the
merchants of Boston. going down the har
Dor to watch the experiments. A boat
built like a scow, called the Sea Bell lad
been fitted with large bell and ringing
apparatus This boat was towed TO a
point on the coast off Winthrop. about
eight miles below Boston. when II was
anchored and the bell was lowered into
the water through a well in her bottom.
Then several of the party were taken off
shore In a steamer a distance OF twelve
miles. and were invited to listen at inter-
walls at a receiver, for sounds of the bell
rung under water from the scow.
The results of the experiment are tes-
titled to by those who heard the bell. in.
the following statement. signed by all
present:
We. the undersigned. hereby certify
that we have this day heard the sub
merged bell fstruck electrically from the
experimental station on board the Sea
BelD through the electrical receiver Sub
merged from the deck of a steamer en-
gagged for the purpose) at distance CT
one and one-half. four, eight and twelve
miles in the open sea. At one and one
half miles the sound OF the bell was heard
var,, loudly and very distinctly. AT four
miles the sound was quite as distinct and
almost as loud as at one and one-half
miles: at eight miles the sound was quite
as distinct as at one and one-half miles.
and almost as loud as at four miles: at
twelyes miles the sound was heard al
times quite distinctly and at times some
what feebIy Even at twelve miles the
sound received was sufficient to give a
warning signal.
The hell was also heard in the forehold
of the steamer, without any receiving ap-
paratus whatever, at a distance of one
quarter mile. so distinctly that il seemed
10 be right alongside the ship, and at a
distance OF one and one-half miles 1t was
heard family hut Enthusiastically, in the
same position in the hold and without"
The only serious experiment ever made
heretofore with sound under water was
made AT Lake Geneva, Switzerland, about
fifty years ago. II was then SHOWN thac
sound travels under water at the rate of
4 zoe feet a second. Through the air it
travels hut 100 feet second. Mr.. Mundy
and Prof. Gray. however, found the exact
speed to be Alp feet after repeated expert |
ments and that it is practically invariable. |
The receiver used in the new system is
a wonderful instrument, inasmuch as II |
shows not only what the sound is. hut |
whence II comes On a coast equipped !
lg nf sE4ra1 .tTI