The Democratic advocate. [volume] (Westminster, Md.) 1865-1972, 1921-03-04
HARDING USED
Is LOUD SPEAKER
DEVICE WHICH THREW
VOICE OVER VAST DISTANCE
ON MARCH f..
HUNDRED THOUSAND HEARD
Tremendous Energy Developed BY
Hidden Amplfers And Motors
j Telephone Principles
I Involved.

Washington, D. C.-For the FIRST
time in the history OF the United
States an inaugural address was heard
by everyone OF the hundreds OF thou.
sands Of men and women who crowded
the broad open space which stretched
for fifteen hundred feet IN every direc.
tion around the inaugural stand 10
front OF the Capitol Building, The rea
son for this was found in the loud
speaking device which was installed
for the benefit OF the public, and which
was the only feature OF the entire sim.
pie inaugural ceremony outside Of the
taking OF the oath BY means of this
device, which is hidden from the eye,
the human voice is made to carry half
q mile under perfect conditions.
II was a system of motors, genera.
tors, wires, transmitters. amplihers
and other electrical machinery de.
signed by the experts OF the Bell Tele,
phone System, which contributed the
speaker to the inaugural ceremonies
for the benefit Of the public. 1t lie
uOA u NbAIluCiNiAl dEf wv - ~ NV
patented, nor Is It for sale or for rent.
To the experts, the system Is the ex.
position OF the development OF every.
thing scientific in the telephone world,
for the principles involved are those
Of the telephone and the engineers and
research men Of The Chesapeake and
Potomac Telephone Company and the
American Telephone and Telegraph
Company, simply brought into play
some Of the marvellous discoveries and
developments Of The Bell laboratories.
All Apparatus Hidden.
Although there were three rooms
full of machinery and electrical Tie.
vices in connection with the loud
speaker, none OF II was IN evidence,
and the huge horns through which the
speech was heard were camoueaged
the speakers stand. So far as the
speaker himself is concerned he saw
nothing Of the apparatus except small
transmitter boxes which were set
somewhere In front and to the sides
OF his speaking desk, so that his voice
was caught In the workings OF the
loud speaker no matter which way he
turned
When the President.elect spoke. MS
voice generated energy by means Of
the transmitters This energy was
transferred BY wires to the complex
apparatus Installed under the Capitol
steps. The energy is led into a little
glass bulb, which the experts call
vacuum tube ampllher," the function
OF which Is to receive energy. multiply
It and sent II on the other amplihers
until II reaches a stage sufficient 10
turn II loose in voice form through the
hidden horns out to the distant crowds
While the speaking was In progress,
q dozen experts were watching each
bit Of apparatus. There were men az
certain points on the capital plaza con.
nected with the machinery rooms by
telephone, TO report to the men at the
ampliRers Tho working loud speaker
requires crew as large as small
vessel
AmpIlfies Millions OF Times
The voice, when 1t energies from
the horns, is almost an exact dupiica.
tion OF the original, but greatly In.
creased In power It is possible for
the loud speaking system to obtain an
application Of several millions times
without great distortion OF the original
wave form.
The mouths of the hidden horns are
depressed just enough 80 that the au.
dience near at hand within range Of
the speakers voice direct, hear very
little from the horn, those further
away hear both the speaker and the
loud speaking system, those furthest
away hearing the horn only.
1t might seem that this add liunal
source OF sound, might create double
effect or an unnatural effect. but II
does not. The sound from the horn is
exactly in phase with the speech, and
almost exactly the same quality At
any point where the sound from the
horns is heard II is practically I'M.
possible to tell that one Is not listen