Juniata sentinel and Republican. [volume] (Mifflintown, Juniata County, Pa.) 1873-1955, 1883-09-12
Fog Signals.

The principal fog signals used in thi
country are the siren, the steam trum
pet, the steam whistle, the whistIin
buoy, the bell boat. the bell buoy an
heavy bells ruag by clockwork. Th
siren is sounded by driving steam
through fat, circular disc, containing
a number of Sits, the disc being fixet
IN the thro of an nimmense trumpet. Be
hind this is a revolving plate. having il
it similar number of openings. Tn
plate is revolved by steam 2400 time.
each minute. Whenever the slIts in tn
plate coincide with those in the disc
Jet of steam escapes through each open
trumpet. Ii there are ten opening
there will be "a 900 screams each mIn
ute. These comoined in the trumpe
give a single, strong shrek in deafen
ing volume, a1d Of great range. Tn,
sound can generally be heard at dis
tance of twenty miles, and can readily
be distinguished from all noises at sea-
The sren Is the farthest reaching fog
signal vet produced. but it is the mos
expensive to build, the most difficult tc
run, and the most costly to keep going.
One of the largest size sirens is connect
ed with the light house at Cape Henlo.
pen, at the mouth of Delaware Bay, op.
poslte Cape May, where i'll fog it gives
blast SIX seconds long after an interval
of 80 seconds. These instruments have
done so well on our coasts that other
countries have procured numbers of
them. Great Britain has more than
twenty of them now in operation on her
shores.
The DaboIl fog trumpet is made like
a monster clarionet, and Is sounded by
air condensed In a reservoir by machIn-
cry driven by hot-air engine. The
largest trumpet Is IL feet long, with a
/, mouth SO inches across and q throat 81
inches in diameter. Its reed of steel is
ten inches long, 2. wide, an inch thick
at Its fixed end and half that at the
other. The Ericsson engine that drives
it has 32-inch cylinder, which. at
twenty pounds pressure, can give five
second blast every minute. The Daboll
trumpet, is, however, going out of favor
because of its liability to accident and
the difficulty of getting it repaired. The
nearest one to US Is In Long Island
Sound at Execution Rocks Light Sta
ton. The most frequently used for fog
signals of this general class is the loco
varying from to Is inches, operated
by an ordinary boiler, under a pressure
varying from so to 100 pounds. By in
tervals of blast and silence ii can be diff
ferentiated from neighboring fog sig
mails, and these intervals automatically
produced by having an engine take
steam from the same boiler, and open
and close its valves at fixed times, when
the steam is smut off or let on as desired.
These instruments do not easily get out
of order, and they are readily operated.
The whistles are used on light ships as
We'll as light houses. There is 12-lnch
whistle on each of the light ships on
Five Fathom Bank, off the Capes of the
Delaware.
The power of these fog signals can be
expressed in proportion thus: Siren, 8;
whistle, Z; trumpet, 4; and as to cost of
running them they stand as follows: ST.
ren, 8; whistle, 3; and trumpet, l.
There are 66 fog signals now on our
coasts operated by steam or hot air.
The bell boat, which Is at best a
clumsy contrlvance, liable to be upset
when most needed, costly to build, hard
to handle and Gltkcult to keep in repair,
has been superseded by Browns bell
buoy, which was invented by an officer
of the Light House Service. The bell
is mounted on ths bottom section of an
iron buoy. which is decked over and
fitted with frame work of 3-inch angle
iron, 8 feet high, to which $40 pound
bell is ngidly attached. A concentric
grooved iron plate Is made fast TO the
frame under the bell and close to 1t, and
a cannon ball is allowed to roll on this
plate, As the buoy rolls on the sea the
ball rolls on the plate. striking ore side
of the bell at each roll. This signal is
always at work, and the heavier the sea
the louder the sound of the bell. There
are "a of these bells now III use in this
country, one of which Is on Brown
Shoal. Delaware bay. They cost, with
their mooring, not far from 81 900
each,
The "whistling buoy" consists of an
iron pear shaped ball, say % feet in di-
ameter, with tube 20 inches across
and 40 feet long running through it.
The water in the the tube acts as pis-
ton to draw in the air through a hole
covered with a retaining valve, and to
expel it through a ten-inch whistle,
a shrill moaning sound which can be
heard several miles. Its dimensions
have recently been reduced without de-
creasing its power. As its action de-
pends on rough water, it is only used
in open water. They now cost, with
their moorings, about 81 200 each.
There are % of them ON our coasts, 5 of |
which are in our immediate waters. |
The whistling buoy recently placed on
the outer Hatteras shoal, just off the
pitch of the cape, is of greatest use to
our coasters. The bell fog signal most
in use is the bell struck by machinery |
moved by clock work. There are about
12O of these bells. They weigh from
300 to 5000 pounds each. though not
many weigh more than l 900 pounds.