The Bemidji daily pioneer. [volume] (Bemidji, Minn.) 1904-1971, 1919-05-02
" WAR \ 4 II, INV INVENTIONS
./C0h|NC TO LIGHT
Many Interesting Achievements
Are Now Being Made
Public.
SEAL OF silence BROKEN

HtRl Uf StlEHGE DnUnLN
arstem Of Sending and Receiving
Wireless Telephone Messages at
Same Time and Rarrage Re-
eelver Among Novelties.
d. New York.--As the seal placed upon
Ae activities Of Americas inventors
~ the war Is broken. news Of many IN,
seresting achievements unknown 20 the
anbltc during the conflict are being
Wrought to Hight. A system Of sending
me receiving wireless telephone met
sG1es at the same time. as Is done In
Ssre lines q "barrage receiver which
shuts out the sound Of all wireless y.
Asation except those which the opera.
Se wishes to hear, and system Of
sapld and accurate photography OF
wireless message became known to the
vahlic for the FIRST time recently, al
though government naval stations have
heen experimenting with them Tor
some time.
Engineers Of the General Electric
sompany at Schenectady are respensi-
1se for each Of the inventions. Ernst
Y. w. Alexanderson, consulting en-
gtneer of the company, told Of the de-
aeaapment of the barrage receiver and
wireless telephony ideas at meeting
4 the Institute Of Radio Engineers at
II West Thirty-ninth street recently.
q A. Hoxie of Schenectady. another
asneral Electric company engineer. Is
the inventor Of the wireless photo
graphic apparatus.
Sending and Receiving.
Doctor Alexanderson told the engi-
aeers that obviously some system OF
aaMultaneous sending and receiving
Hsuld have to be invented before wire.
Ass telephony would ever become COM
sercfally practicable. Switching from
me apparatus to another to send and
receive would be annoying and delay
ang. For instance, the user Of the tele-
SAone on this side of the Atlantic says:
Hello into the .mouthpiece. Then
Ae has to switch to another apparatus
% catch the answer from Europe. And
perhaps his friend overseas Is doing
me same thing. and the attempt at
sonyersation develops into q sort Of
ASde-and-seek game. There was also
ne problem of bringing the wireless
aaasphone to the home OF the user. II
,sas has to travel to Washington or
REV Brunswick to use the wireless tel
sRhone it Is scarcely saver of time
NJ money. ~
Doctor Alexanderson has devised a
sJstem Of separate sending and re-
seiving antennae. the sending and re-
reaying stations interconnecteds by a
xire line and further connected to the
exchange Of the local telephone sys-
ts1n, so that all Mrs. Jones has to do
1hen she wants to find out what, Mr..
Homes Is doing In Paris tonight lis to
I'D to her telephone and ask, not for
TOR operator. but for the Wireless OPP
.rator. he will connect her with Mr..
Homes. nv M
The earrage Receiver.
The Invention of the Marriage re-
aelver came about as a, result df the
,spnSusion into which the wireless ma
ehinery was thrown during the war.
Through her powerful stations at Nan
cen and elsewhere Germany was mali
.ionsiy flooding the atmosphere with
wireless noise" 80 that communica.
tions, between France and England
aid America became very difficult.
germany was completely drowning out
NE voice Of Americas allies. The In
snrallied conference in February. 1913.
rsgught q way out Of the difficulty. and
sppeals for a solution were brought to
Doctor Alexnnderson by Lieutenant
Yaeernot Of the French mission In this
ioEntry. The solution, which was
adopted BY the French and American
governments after Its first sdemOnstra-
sfon was called the "barrage receiver"
Asceuse the word "barrage" has the
srigieaE meaning Of stoppage proven.
ason. The barrage receiver success
sulyl shut out the vibrations sent out
tfesn Germany with the object Of de-
sSreytng the allied .intercommunica-
son. Its principle can be compared
"a that Of an instrument which. II ap-
nifed ia the ear. would silence the
shslsktng Of o. steam whistle ten yards
away. while enabling the listener to
near perfectly the spoken word hum
fred yards of. Aside from its war
sfsns use the barrage receiver has ex-
ssRsive possibilities for peacetime de-
reiopment. Through its use the num-
Asr OF communications that may be
rarried on without disturbing each
stfer may be multiplied greatly.
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