Worcester Democrat and the ledger-enterprise. (Pocomoke City, Md.) 1921-1953, 1921-03-05
SPEAKING DEVICE
HELPS INAUGURAL
New Apparatus Makes 1t Possible
y For Everyone To Hear President
Harding's Address.
USED FOR THE FIRST
TIME ON FRIDAY

For the first time in the history Of
the United States an inaugural ad.
dress was heard in Washington by
Everyone of the hundreds of thous
and of mel and women who had
stretched for fifteen hundred feet in
front of the inaugural stand at tn
Capitol Building. The reason for
this is found in the loud speaking de-
wee whcn h;.d been installed for the
benefit of the public and which was
the only feature of the entire in
augural ceremonies 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
a mile under perfect conditions.
The apparatus is a system of mot
ors, generators, wires, transmitters,
amplifiers and other electrical ma
clinery, designed by the experts of
the Bell Telephon2 System, which has
contributed the speaker to the inaug-
ural ceremonies for the benefit of the
public. 1t is not a commercial device,
it is not patented, nor is it for sale
or for rent. To the experts, the sys-
tenn is the exposition of the develop
ment of everything scientific in the
telephone world, for the principles in
volved are those Of the telephone and
the engineers and research men, of
The Chesapeake and Potomac Tele-
phone Company and the American
Telephone and Telegraph Company
have simply brought into play some
OF the marvellous discoveries and de
vclopments of the Bell laboratorie
Although there are three rooms full
oi machinery and electrical devices in
connection with the loud speaker,
rome of it is in evidence, and the huge
horns through which the speech was
heard were camoufaged by being
made part of the roof of the speak
er's stand. So far as the speaker him
sell is concerned he saw nothing
Of the apparatus except small trans
nitter boxes which were set some
where in front and to the sides of his
speaking desk, so that his voice coulu
he caught in the workings of the
loud speaker no matter which way he
turned.
When the President Elect spoke
his voice generated energy b.!
means of the transmitters. This en-
ergy is transferred by wires to th@
complex apparatus which was install
cd under the Capitol steps. The ener-
gy is led into little glass bulb,
which the engineers call a "vacuum
tube amplifier," the function of which
is to receive energy, multiply it and
send it to the other amplifers unt
it reaches a stage sufficient to turn
il lose in voice form through the h.I'
den horns out to the distant crowds
While the speaking was in progress
. dozen Bell experts were watching
each bit of apparatus. There werl
rlen at certain points on the Capitol
plaza connected with the machinery
rooms by telephone, TO report to the
l. en- at the amplifers. The workin?
loud speaker requires crew as largo
as a small vessel.
The voice, when it energies from
the horns, is almost an exact dupll-
cstion of the original, but greatly in
creased in power. 1t is possible fo,
tie loud speaking system to obtain
-an amplifcation of several millio:
times without great distortion of tl''
original wave form.
The mouths OF the hidden horn
are depressed just enough so that The
audience near at hand within range
of the speakers voice direct, hea
little from the horn, those further
away hear both the speaker and the
loud speaking sysem, those furthes
away hearing the horn only.
1t nigh seem that this additiona
source of sound might create double
effect or an unnatural effect, but /
does not. The sound from the horn il
exactly in phase with the speech, ant
almost exactly the same quality. A
ary point where the sound from tn
horns is heard, it is practically i'm
r. ssible to tell that one is not liste~
ic to the speaker himself.