The morning news. [volume] (Savannah, Ga.) 1887-1900, 1893-08-21
THE LARGEST IN THE WORLD
A Search Light at the Worlds Fair
of 375 .OOO. 900 Candle Power.

of 375, 100000 Candle Power.
To America belongs the honor of CON
STRUGGLING the largest and most powerful
electric search light in the world, now
being set up at the worlds fair 1t stands
about 10 feet inches high to the upper
side of the ventilator on the top of the
drum, and the total weight is about 5000
pounds, but so perfectly is it mounted
and balanced that child can move it
in any direction It was built
by the General Electric Company. The
rejecting lens mirror used in this pro
jector is $50 centimetres, or 90 inches, in
diameter. 1t is cOncave spherical mir
ror of the Mangin type, free from spher-
ical alteration, rejecting a sensibly
parallel beam of light. 1t is a most per-
feet specimen of optical work, three and
one-fourth inches thick at the edges and
One-siXteenth of an inch thick at the
centre, and weighs about 800 lbs. The
metal ring in which it is mounted weighs
about $50 lbs, and the total lens, ring and
cover weigh about 1,600 lbs.
HOW IT Is MOUNTED.
This great mirror is mounted at one end
of the big drum, the outer end of which
is furnished with a door, consisting of a
metal rim in which are fixed a number of
plate glass strips tive-sixteenths of an
inch thick by six inches wide. Inside
this drum, and sliding upon ways ar
ranged on the bottom is placed the cleo
trio lamp, the source of the light which
is reflected by the mirror. 1t is entirely
automatic in its action, is six feet high
and weighs about 400 pounds. The car
bOns used are also made especially for it.
The upper or positive carbon is one and
One-half inches in diameter and twenty
two and one-half inches long, with a FIVE
siXteenths of an inch core of soft
carbon running from end to end
through its center. The lower or
negative carbon is one and one
fourth inches in diameter, is fifteen inches
long and also has core of soft carbon
running through its centre. In addition
it's outer surface is heavily coated with
copper The positive carbon is set a lit
tie in front of the negative and thus al
most all the intense light of the incandes
cent crater is cast upon the reflector
The maximum current at which this
lamp operates is 200 amperes, and at this
current the lamp has luminous intensity
of about 80, 600 to 100000 candles, the re-
fiected beam a total luminous intensity
of about 375, 900, 900 candles, an intensity
which the eye cannot appreciate.
ITS BRILLIANCY BLINDING.
In looking at the side of the beam the
!
light of comparatively low intensity, but
in looking at the beam directly its bril-
liancy is fully seen and the effect is abso-
lutely binding. NentilatOrs at the top
and sides allow a constant current of air
tO.pass through the drum and dissipate the
heat generated by the arc lamp; and they
are so arranged that no light can escape
through them. All the connections for
adjusting the positions of the carbons and
TO the outside, and are arranged in close
proximity to one another at one side so
that all may be manipulated by the
operator without moving from his
position Through openings in the
drum covered by densely colored glass
the opera tion of the lamp may be watched
and its adjustments verified. The drum
is supported by trunnions in bearings at
the top of a Y-shaped fork, set in base
plate and the whole is supported on a
system of friction wheels, forming turn
table resting upon the top of massive
pedestal supporting the whole structure.
The drum, fork, and base plate may be
rotated horizontally on the turntable
either by hand or by gearing provided
for this purpose. The drum may also be
elevated or depressed in a vertical plane
by similar gearing.
THE FIRST PUBLIC TEST.
Before the protector was sent to the
worlds fair, public test was made at
Middletown Conn. From the roof of the
works the great white beam of light shot
forth into the obscurity of the night, and
slowly swept the countryside for miles
around, bringing every object upon which
it was directed into brilliant and distinct
relief. 1t illuminated the roofs of distant
villages and scared their inhabitants,
and lighted up the sign boards miles
away, so that they could easily be read by
means of a glass. The protector was
turned upward towards the sky, and the
beam, like a super natural divine finger,
wrote words upon the clouds-message
of light to the starry populations. 1t was
a majestic manifestation of man's invasion
of the realm of PhBbus
1t was observed that the space within
the beam was violently agitated, and clio
ser observation revealed the fact that
millions of moths and minute insects were
lowering in it, attracted by the brilliancy
of the light. Next morning bushels of
dead moths, beetles, other insects, and
some small birds were swept up from the
roof on which the protector stood. They
had been killed by the intensity of the
light.
How far the powerful beam of light Of
this instrument can be seen is difficult to
STATE The search light set up by the
General Electric Company on Mt. Wash
ington in the White mountains, has n
diameter of only 50 inches, and reflected
light from the mirror ofabOut 100, 900 can
die power, yet the newspaper can be read
in it's beam ten miles away, and the light
can be seen from points 100 miles away.
How much farther then could this 315,-
600. 900 candle power light be seen in a
clear atmosphere free from moisture, if
the protector could be mounted upon an
eminence sufficiently high to clear all sur
rounding obstaclesl