Shepherdstown register. [volume] (Shepherdstown, Va. [W. Va.]) 1849-1955, 1921-03-10
HARDING USED
LOUD SPEAKER
DEVICE INSTALLED WHicHTHREW
VOICE OVER VAST DISTANCE
ON MARCH
HUNDRED THOUSAND HEARD
Tremendous Energy Developed BY
Hidden Ampllfiers And Motors
Telephone Principles
Involved

Washington. d. C.-For the nrst
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
Tor fifteen hundred feet in every direc,
ton around the inaugural stand in
front OF the Capitol Building. The rea.
I 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.
IL was system OF motors. genera
tors. wires, transmitters. amplihers
and other electrical machinery de-
signed by the experts of the Bell Tels-
phone System. which contributed the
speaker to the inaugural ceremonies
Tor the beneht OF the public. It is
not commercial device, 1t 10 not
patented, nor is 1t 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 de
vices in connection with the loud
speaker. none Of it was in evidence,
and the huge horns through which the
speech was heard were camoufaged
by being made part OF the roof Of
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. 80 that his voice
was caught in the workings OF the
loud speaker no matter which way he
turned.
When the President-elect spoke, his
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 a
vacuum tube amplifier," the function
OF which is to receive energy, multiply
1t and sent it on the other amplifiers
until II reaches a stage sufficient to
turn 1t 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 at
certain points on the capital plaza con.
nected with the machinery rooms by
telephone, to report to the men at the
amplifers. The working loud speaker
requires O crew as large as a small
vessel.
AmpIifies Millions OF Times
uc SOlCo, WHEN IL energies from
the horns. Is almost an exact duplica.
ton Of the original, but greatly in
creased in power. 1t 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 so 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, Sc furthest
away hearing the horn only.
1t might seem that this additional
source OF sound, might create double
effect or an unnatural effect, but it
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.
oil IN tal1 t.