The Holly chieftain., 1923-08-16

In order to avoid the Likelihood OF CONFUSION De-
tween lights, endeavor is made to give the lights
distinct characteristics As much Of the coast was
lighted before the Introduction Of modern light
house apparatus, the original lights were as rule
fixed, but at the more important Of these stations
apparatus has now been installed to make the
lights flashing occultng. This effect Ii produced
In the case Of flashing lights by revolving all or
part Of the lens which Is specially constructed with
panels of prism for concentrating the rays into
beams-in the case Of occulting lights by some
form Of travelling screen or shutter which obscures
the light at intervals In either the motion ID
regulated by clockwork with the necessary gov
erning mechanism to cause light and dark periods
In accurate sequence. The terms flashing" and
"occultng" refer to the relative durations Of light
and darkness fash being an interval shorter than
the duration Of eclipse. while occultation IL
shorter than, or equal to. the duration Of light
The first fog signal In the United States was
cannon installed at Boston light in 1719 which was
fred when necessary to answer the signals Of ships
In thick weather. Guns of various types were used
at other lighthouses. but have now been generally
abandoned. Bells were introduced at compare.
lively early date. Trumpets were the next i'm.
provement and steam whistles came into use in
1857. Experiments were made with sirens In 1857
and the first service installation was at Sandy
Hook East beacon In 1885, This apparatus has been
modified and improved until the present automatic
siren using compressed air instead Of steam was
evolved. Practically all fog signals as now In.
timing the strokes or blasts This usually consists
OF cockwork whereby the cycle is repeated
every minute In order to facilitate Identification
submarine signals, which have been introduced
IN recent years. have as rule more effective and
constant range OF audibIity than signals sounded
IN air Such signal consists essentially OF a
specially designed bell. submerged sufficiently to
avoid wave disturbances, with some form of strik
ing attachment. On light vessels the bell In us,
ally swung over the ships side on a chain at
tached to davit and the striking device is one
rated pneumatically to ring certain set Of bIow.
at prescribed intervals.
At light stations the bell Is usually supportad
on tripod. placed on the sea bottom, a short dis
tance away from the light, and the striking
mechanism operated electrically through cable,
with characteristic number of blows at regular in
tervals. When attached to buoys swinging vana
ID provided which Is forced up and down as the
buoy surges In the sea- The motion of the yane
causes spring to stretch and when 1t has reached
sufficient tension It Is released the action cans
ing a blow to be struck on the bell The blow.
are Of equal Intensity, this being due to the elonua
tion Il the spring although the interval between
them varies with the condition of the sea. and M
regular code Of blows Is therefore practicable
In orGer to obtain the best results with .rh.
marine BELLS receiving apparatus, somewhat sIm,
lar to telephone. has been devised for attachnen,
to a vessel. The sound may be heard also on ves.
sells not equipped with receiving apparatua hv
observers below the water line and particulariv in
Iron steel ships.
Since 1885 systematic records have been ken,
Of the number of hours Of fog or thick weather ob
served each year at the different fog.sgnal sta.
tiOns. These figures present Interesting statistics
and are Of considerable value in approximatinr
the prevalence Of fogs at various localities when
proposed new signals are under consideration The
absolute maximum record Of fog was at segun.