Mexico Missouri Message

A NEW MEGAPHONE.

Novel and Complicated Apparatus
Which Increases the Volume
of Sound.

A novel apparatus for increasing the
intensity of sounds has been invented
by Messrs. G. Laudet and L. Gaumont.
The principle underlying the construc-
tion of this apparatus, which was recent-
ly presented to the French Academy of
Sciences, consists in transmitting the
sound vibrations concerned to and from
a convenient flame. After the first ex-
periments made in this connection,
utilizing the human voice, had given sat-
isfactory results, the voice assuming a
remarkable intensity, the experiment-
ers continued their investigations, em-
ploying sources of sounds of mechanic-
ally determined intensity, with contin-
ued success.

The megaphone (shown in the accom-
panying engraving), explains the Sci-
entific American, consists of an equilib-
rated distributor to regulate the amount
of the burning gas mixture, and a burn-
er wherewith the gases are consumed in
an ignition chamber.
The apparatus
submitted to the academy was arranged
for registering the reinforcement of
sounds of any kind on ordinary phono-
grams.
Air and acetylene were em-
ployed as burning gases.

The distributing mechanism consists
of a chamber, A, into which the combus-
tible mixture is introduced under pres-
sure through a conduit, B. A vane, C,
supported on knife edges as at O, is
mounted at the bottom of the chamber,
A, an elastic ring being provided to in-
sure airtightness in O. Any motion giv-
en to the pencil is transmitted to the
vane, C, inside of the distributor. On
either side of C openings, D and D', are
provided through which the gaseous
mixtures are allowed to issue in respec-
tively equal amounts as long as the vane
is immovable. Any displacement of C
will, however, result in an increase of
the amount of gas issuing on one side,
while the amount issuing on the other
side is reduced. The total amount of
utilized mixture remains constant, and
the pressure in the interior of the cham-
ber is also unaltered.

The gases are collected and conveyed
to the burners through a series of con-
duits, E, E, E', E'. The burners consist
of a series of disks cooled by an air cur-
rent, H H', the gases being expanded and
reduced to a temperature such that com-
bustion always occurs in the chamber
F F', just at the point where the gases
escape from the openings of the burner.
The apparatus further comprises two
funnels, G G'. The power of the sounds
obtained, which is truly remarkable, de-
pends on the amount of gas mixture
used and on the energy expended dur-
ing its combustion.