Daily Kennebec journal. [microfilm reel] (Augusta, Me.) 1870-1975, 1911-01-23
Lessons in Science
Popp Brandy System.

\ system designed by Eduard Bran
~ and Victor Popp, OF Paris, con-
sists of an induction coil. and an in
terruptor OF the mercury turbine type
driven by an electric motor. The
ligh-tension circuits include tuning
coil not unlike those previously de-
Scrlbed The chief difference between
this system and the preceding ones
lies in the design of the receptor.
which employs the Brandy tripod
conerer. This consists of two steel
disks, in one of which three metal
rods with rounded ends are fixed,
forming small tripod. The ends.
which are oxidized rest on the pol
ished surface of the second disk. The
Coherer is set at the rear of the reg
lister and when the latter is in opera
ton lever attached TO the armature
serves to tap the coherer. The cur
rent from a dry cell energies the
coils of the polarized relay when the
resistance of the cohercr drops to q
minimum value due to the action of
the oscillations, which impress Their
energy upon it when these are set up
by the incoming electric waves.
In all of the systems which haze
been described in this series of arti-
cles, various means for tuning and
sTntoni2ation are resorted to: but since
the eiectri, waves emitted by oscllla-
tons set UP by descriptive discharge
are in any case periodic. and decrease
in geometric ratio, and moreover since
a long period of time must necessarily
eidpSe between the successive trains
of waves, the resonance effects OBJ
tanned by these means are not nearly
great enough to make Sclectiye signal.
ing possible. An open circuit danps
out the oscillations in one or two
swings and though the oscillations in
Il closed circuit are much more p"rA
sistent, even under the most favorable
circumstances they are by no means
continuous. Ii electric oscillations
could be set up that would take on
sine wave form and be continuous.
instead of periodic, Il degree of reSo-
nance could be obtained between Il
transmitter and II recptor tuned to it
that would enable the latter To re-
spond to the former and keep all
others out thus following the analogy
of the sympathetic tuning forks.
TO obtain sustained electric oScilla-
tons Naldcmar Poulsen, Of Copenha-
gen, has designed 4 new type of gem
orator in which the spark gap plays
no part His transmittcr is based up
on an effect first noted by E!hn
Thomson in 1893, and which vas
brought out in 1900 by w. Euddell un-
der the name of the musical are. The
apparatus consisted of an arc light
fed by a direct current and around
which is shunted condenser in series
with an induction coil When certain
conditions are satisfied the arc light
will give out musical note and at the
same time will transform portion
OF the direct current into alternating
currents which are constant in ampli-
tude. Acting upon this suggestion
Poulsen succeeded in increasing the
frequency of the currents produced in
tie secondary circuit by placing n
spirit lamp under the arc. producing
oscillations at the rate OF millions per
second When an ordinary ammeter
WIS placed in the direct current cir
cult and hot wire ammeter for meas
uring high-frequency currents was in
serted in the closed condenser circuit.
the meters indicated that about 80
per cent. of the initial energy OF the
direct current was transformed into
electric oscillations, while the ratio of
transformation was increased to so per
cent. when the arc was formed in
hydrogen gas.
TIL" advantage of employing such
sustained oscillations for the produc-
ton and propagation and reception of
electric waves for wireless biography
is obvious. and by properly tuning the
sending and receiving open and closed
circuits. any length of wave can be
produced and utilized and the maxi
mum resonance effects thus obtained.
Ii is stated on good authority that Il
dozen messages have been sent and re-
ceived between as many sets OF in
struments without interference. and
If this extraordinary result can be
duplicated over distance of 100 miles.
as the tests between the inventors
proving stations indicate. an advance
has been made in the art that is sec
ond only to the introduction of wire
less telegranhV itself