Richmond dispatch. [volume] (Richmond, Va.) 1884-1903, 1894-07-24
A POWERFUL FLASH LIGHT.
1t Will he on Fire Island and VIII Have
100000, 900 Candle Power.
fNew York WORLDLY

Besides the electric search-light with
which experiments have lately been made
at Sandy Hook, New York harbor will
be lighted before the summer has passed,
by another electric light even more power
ful. The search-light. which has an esti-
mated power OF 20cc000 candles. be-
longs to the United States army. and Is
TO be used In time OF war for signalling
and TO examine at night all the APP
proaches to the harbor. The second light
will be erected At Fire Island. Ii will be
a hash-lght. part of the lighthouse es-
tablishment, and is intended as All aid
TO navigation.
This hash-light consists of bivalve
lens about eight feet in diameter. to be
illuminated by two arc burners of sew
eral thousand candle power each. so mag
nfied 10y the lens as TO give a flash whose
power is estimated at 2s0.cp.Oo0 candles.
This light will have the most powerful
lens ever constructed. and, in favOrab bic
weather its rays. projected against the
sky, Will be seen at "A d.stance of at least
100 miles. while the light itself. which will
flash every five seconds, will be visible
twenty-fOur miles. For the sake Of COM
parison, il may be stated that the torch
Of the Statue Of Liberty. with which every
New Yorker is familiar. is only 500
le-pOwer. The FIRE Island search
light will be 500OO times "a brilliant. but
that vast difference will scarcely be ap-
probable. for II has been found that after
the power Of the few thousand candles
has been reached IL is dfhcult to note
the full effect from the addition Of a few
thousand more. and that the human eye
is incapable Of distinguishing the excess
of brilliancy OF one very powerful light
over another.
Fog will be the greatest enemy Of the
search as well as Of the hash-lght Eu-
rOpean electricians unwillingly acknON-
ledge that electric light has not so great
penetration through fog or haze as the
ordinary gas or oil lights. The most
powerful light on the English coast Is
on the Isle OF Man, for which an H.
Eliminating power Of 10000 candles il
claimed. Sailor-men say they could see
II as far Ia f0ggy weather II IL had but
3.se0-candle power. That the 1000 90
candle-power light at GATHERINGS Point
is equally invisible In thick weather was
unhapply proved last autumn by thu
loss Of the steamship Elder near that
lighthouse.
The most powerful electric light on
the French coast is at Cape lie Heve
three miles from Ilayre. which has -.
0On.c0 candle-power. but IL will soon be
exceeded b. a light 10 be erected at
Penmarck. Iiisterre and to be of iG0oJ,-
co. andle-pOwer. II is estimated that
this latter light will be visible sixty
miles I'm average weather. twenty-five
miles in foggy weather, and loo miles on
"a clear night, when projected against
the sky.
The new bivalve lens for the Fire-Islsnd
hash-light Is stored at the lighthouse Ia
ton. Tompknsville. ). l. The two sides
Of the bivalve, eight feet in diameter. are
about six feet apart. and each lens IL
made up OF many crystal prsms fixed into
network of brass. the pri-ms cOncen-
trating the ray of light upon crystal
disk in the centre. Clockwork machinery
will revolve the light and 10 reduce the
friction To the lowest point. nearly the
entire weight of the whole mechanism will
rest on column OF mercury. The light
HORSEPOWER on which it will be erected
will be lbs feet high.