The Progress., 1893-06-24
EIEG'7.BICAL DISPLAYS.
,,+eres.ing Sights at the Great
Worlds Fair.
,r,,oS IN ELECTRICITY HALL.


WORLDS FAIR, June I'll lspecisLl -
tbe most curious displays in the
v,a.trical BUILDING is the magic pencil.
I.-ca script letters made OF ofterent col .
IL electric lamps form the initials OF the
wastern Electrical company, and behind
.,ou, isa pole or stick, supported by small
[ '-;-es and resembling a huge pencil. This
'.,ciI is all the time in motion, its move
- beiag automatically controlled. 1t
- at the top Of the "W," and follows
'IaI;,es Of that letter two down strokes
1,,youn strokes. Then it jumps over
.ho "E" and finally traces the Go"
wherever Il touches, or appears to touch,
,.i.aves n trail of fire behind it. The first
.t;no IL do is 20 illuminate the topmost
- of the "W," ," and then the next lamp
halow burns brightly, and the third and
al the others in turn.
The effect IS just as If some unseen hands,
,,iAed by intelligence and purpose, were
roving the big pencil and writing the
.h.-,cters literally in letters of fire. As
.oon as the pencil has completed its task
,.,otes esthe back track, retraces the lines
o,,be letters one after another, eXtinguish-
;,olamp after lamp in its progress. The
,wo movements together give q perfect
uusiou of the writing of letters in vivid
lines and then rubbing them out again.
Rut it is only an illusion. The pencil,
.samatter 9: fact, has nothing whatever
,odo with the lighting or extinguishing
ofthe lamps. That is only part of the
theatrical effect designed to deceive the
o,Iooker. Il does so most successfully.
In nractice the lamps are lighted and eX-
tin1uished by means of an automatic
switch-a contrivance by which the cur
rent il turned on one lamp and then an
otber in the series as regularly as tooth
after tooth in the escapement wheel of
watch is brought into play, and on much
the same principle. 1t is very ingenious
device. Turning on and off the current by
means of revolving cylinder whose pc
rinlery carries a series of contacts, is SIM
ME enough. Tie complicated part of the
machine is the oscillating pencil, and this
il mechanical. BY arranging the base Of
aroi or pencil between a series of rollers
of uneven surface which are in motion a
certain orbit of movement is given to the
free end: and in this case the rolls are so
arranged as 10 make the orbit correspond
10 the lines Of the desired letters. The
cylinders are automatically reversed at a
certain point and this causes the pencil to
retrace the lines which it has seemingly
drawn. No more successful device than
this is to be found in the spectacular part
Of the electrical show.
Another very interesting illustration of
what may be done with electricity is
shown near by, and it has the immense ad-
vantage of being useful rs well as pretty.
Near the center Of the Electricity building
stands steel mast about forty or fifty
feet high Hung upon it, at different
nights. are four powerful electric lamps.
First they are all white, then all green or
red Now one Of them only is white, or
only one Is red In few seconds two may
be red and two green, or three green and
one red. The number of changes which
may be made with four positions and four
colors Is very great, as we see by watching
the combinations which are shown on this
staff in rapid succession. We are puzzled
TO know what all this is done for-what
useful purpose it serves, and we press for
ward to investigate.
At the base OF the steel pole stands a
young man with box on n table by his
side The box is about as big as a cheese
box, and its top is OF glass, and subdivided
into small parts similar to the keys of a
piano or organ Each key is marked with
aletter OF the alphabet, or with two or
three letters in combination. A little
crank runs over the dial-plate, and we no.
tice that when the man in charge moves
the crank to cover one of the characters he
presses on a key and forces a little pin
down upon that piece of ivory. The effect
isinstantly 10 change the location of the
colors on the staff
Now We understand it. The attendant
ineharge offers explanations, but the de-
vice Is SO simple that explanations are
really superfluOus. This box is simply a
switchboard. The characters on the keys
are the naval signal-code. The steel mast
corresponds TO the foremast of a man-of-
war, where the signals are displayed.
When the attendant places the crank or
switch at the key reading "JA," for IN
stance Qf my memory fails to give me the
correct letters it doesn't matter. for the
principle of operation is what we are after, a
green light shows at the top, next below il
Nef ehiIu q blue anu dO Juc DOJNOlll
Wnite. The meaning of this signal is "We
are about TO send boat to you with dis
patches" By a simple touch of his finger
tne man in charge of the signal box has
uttered all this in unmistakable letters OF
nre, to be read several miles away, if needs
c' by the officer who stands glass in hand
Watching for signals.
Ihe operation of this method of night
signaling on shipboard is so rapid and
SIMPLE that an extended conversation car
now be carried on in the time which was
necessarily devoted to the expression of q
single code sentence under the old plan OF
running up and hauling down lights
mus we see that electricity is in more
ways than ore a boon on shipboard. Not
only does it work the signals, illuminate
,ne interior Il the ship and fill the search
nsn's with powerful radiance which dis
e'oses the presence of any craft for a mil,
around, but it is used to strengthen tbs
magnets of the compass on steel ships anC
opropel forms OF torpedoes against tn,
ssnemy who dares approach within strik
ing distance.