The morning news. [volume] (Savannah, Ga.) 1887-1900, 1898-07-17

three and one-fourth inches thick at the
edges and one-sixteenih of an inch thick
at the center. II weighs about 800 pounds
The metal ring in which 1t Is mounted
weighs about $50 pounds, and the total
lens, ring and cover, weigh about 1000
pounds. This great mirror Is mounted at
one end of the big drum, the outer end Of
which is furnished with a door, consisting
Of number of plate glass strips. In
side the drum and sliding upon ways
arranged on the bottom, is placed the cleo
trio are lamp, the source of the light
which is reflected by the mirror. II is en-
tirely automatic i'm its action, Is six feet
high and weighs about 400 pounds The
carbons used are also made especially for
it. The upper or positive carbon is one
and one-half inches In diameter and
twenty-five and one-half inches long. The
lower or negative carbon Is one and one
fourth inches I'm diameter and fifteen
inches long. The outer surfaces of the
carbons are heavily coated with copper
The positive carbon Is set little in front
of the negative and thus almost all the
intense light of the incandescent crater Of
the arc is cast upon the reflector.
At the maximum current at which this
lamp operates it has a luminous intensity
of about 10000 10 10000 candles-the re-
hocted beam a total luminous intensity Of
about 375, 10000 candles an intensity
which the eye cannot appreciate In look
ing at the side Of the beam the spectator
only distinguishes stream of light Of
comparatively low intensity but in look
ing at the beam directly the effect is alb
souteiy binding Ventilators at the top
and sides allow constant current Of air
TO pass through the drum and dissipate
the heal generated by the arc lamp, and
they are so arranged that no light can es-
cape through them to confuse the oper-
ator. All the connections for adjusting
the positions of the carbons and the lamp
are brought through the drum to the out
side, and are arranged in close proximity
to one another at one side. 20 that all may
be manipulated by the operator without
moving from his position Through OPEN
ngs in the drum covered by densely col
ored glass the operation Of the lamp may
be watched, and its adjustment made The
drum is supported in bearings at the top
of a Y-shaped fork, set in a base plate,
running on small wheels, forming a turn
table, resting upon a massive pedestal sup
porting the whole structure. The drum,
fork and base plate are rotated horizon
tally on the turntable, either by hand or
by mechanism. The drum may also be
elevated or depressed vertically.
For the past two years This great light
has shone over the waters OF the Pacific
from the top Of Mt. Lowe From the top
of the mountain the great white beam of
light has shot forth into the obscurity OF
the night and slowly swept the country
side for miles around bringing every OBJ
iect upon which 1t was directed into bril-
liant and distinct relief 1t has iilumina ted
the roofs of distant villages and scared
their Inhabitants, and lighted up the sign
boards miles away, so that they could be
easily be read by means Of glass. The
protector was frequently turned towards
the sky and he beam, like a supernatural
finger has written words upon the clouds
It's use will now be less peaceful In the
hands Of skilled men on the fortificadons
It will continually sweep at night the
waters adjacent 10 San Francisco, reveal
ing any suspected boat or vessel that an
enemy might send 10 attack us from that
side.