The daily Gate City. [volume] (Keokuk, Iowa) 1855-1916, 1911-08-31

we're found Inadequate There was but
one lamp best suited to the exacting
needs OF the moving picture machine
and that was the powerful ten and
twelve thousand candle power arc
lamp available only from direct cur
rent. AS most cities and villages
| where electric lights are used have
only the alternating current systems
these direct current lamps were I'M
suitable. Happily electric engineers
are ingenious and resourceful men,
and most of the difficulties, which
have from time to time INSTRUCTED
their paths, have been finally sur
mounted. 1t was not very long before
one of these engineers hit upon the
plan of utilizing the mercury arc recti-
! fer for this purpose.
The mercury arc rectlfer is won
! derful little device. All that can be
| seen Is peculiar shaped glass tube
| about the size Of a large gourd in
which pool Of bubbling and boiling
mercury emits beautiful blue-green
light. This device will effectively
| change alternating electric current
into direct current with very little
loss The current enters the tube in
1 cycles, or surges, flowing first one way
and then the other over the wires as
4 often as sixty times a second, and
when 1t leaves this tube it is rectified
or changed into direct current, flowing
one way only. This direct current is
| led to the arc lamp where it is changed
/ into a powerful white light which is
|, the nearest approach to actual sun
shine of any artificial illuminant.
Electricity is also used to consider
able extent in modern moving picture
! theatres The interior of the theatre
is lighted with green-shaded mean
descent lamps which give modified
light, sufficient, however, to enable
those entering from the bright outside
to readily find vacant seats Electric
fans cool and ventilate the buildings;
electric cigar lighters are provided in
the vestibules and electric announcers
are used to indicate the titles of the
i pictures. An electric ozonizer is also
used in moving picture theatre at
Schenectady, N. Y, which keeps the
air sweet and pure.
i The natural inference is that we i'm
mediately get flood of light when
we turn the electric switch. While
this is true enough in sense, many
things really happen before we get
the light. And the light is not in
Simultaneous at all, even if it does look
so.
4 The first thing accomplished in
turning the switch is to close the cir
cult so that the electric current can
flow readily through the wires. The
electrical energy rushes along the sur
face of the insulated copper wires al
!, the terrific speed of $4,000 miles q
second If these wires were not prop
erly insulated the electricity would
tend to leak off the wire to some other
good conductor at the first opportun
ity, as it is ever seeking the shortest
: path through it's circuit. When this
energy, rushing at terrific pace
reaches the electric lamp it passes
readily enough through the small
iron and platinum wires into the built
. where it meets with it's first resist
ance. In its paths stand tiny loops O
fine metallic wire which Is not
good conductor of electricity. Witt
all the pressure behind it the electric
al energy tries to surmount this OBJ
stacle in it's path. 1t pushes ane
forces it's way through the obstruction
and this requires tremendous
amount of work, just the same as 1
would require a tremendous amour
of work for man to climb the face
, of a cliff This work consumes the
electrical energy, just as 1t would
consume mechanical energy, or HUI
man energy, and the energy thus con
suned is not really consumed or de
, stroyed-for nature never totally de
stroys anything, but changes it int
heat.
AS the current forces its wa,
/ through the fine wire the electrical
} energy is rapidly changed into hea
and this heat quickly brings the wir'
3 to a white glow, when, by strang'
t coincidence, it is fairly good con
| ductor. While the light seems in
t Simultaneous it is only because it Is to-
1 quick for the eye. In reality the wir
t first gets warm, then hot, then dul
!. cherry red and finally this red fades
: as it gets hotter, to white hot gloy
4 which is maintained as long as tn
current is turned on. The heat re
E sultant from this process Is rapid
V dissipated into the air
S obviously light is the one importan
: factor in making city attractive an
e beautiful at night, yet how man
J cities are there which are dark an
V fearsome Just as soon as the sun sink
4 behind the western hills. How man
n cities where few feeble Tights
s strung at long intervals in an irregt
S lar. wavering line, try in vain to dis
r pei the darkness.
The best lighted city is always tn
t most attractive city; it is also tn
J. best advertised city and usually on
n of the most progressive cities
~ e.