The Washington herald., 1909-01-31
WRITES And TALKS.
Telewriter Rivals the Tele-
graph and Telephone.
THE SENDER USES A PENCIL
Receiver Reads Message a. Regis
tered with Pen at Other End Of
WIre-Switching on TraRzmitters,
Line Is Opened for Converse
tioa Between Parties.

The "Telewriter." an instrument for
the electrical Transmission Of handwTit-
ing, IS Of much scientific interest and
practical utility. while its commercial i'm
portance is emphasized by the granting
by the British pOstmaster-genersl Of
twenty-one years license TO establish ex-
changes for the use Of the telewTiter
throughout Great Britain, and to allow
telephone communication as an aux
Iiary 10 the use Of the new instrument
Il is the invention, according 70 the
London Times. Of Mr.. Foster Ritchie. a
Scottish electrician, who made his first
model about twenty years ago. It Is
daily proving It's utility for the instan-
taueOus transmission Of written mes
sages from place 20 place, and expert
ments have been made for the transmits
sion, not merely OF writing. but OF
sketches between London and Msnches-
ter. For practical purposes it has been
found possible to transmit written mes
sages over a telephone circuit up to q
distance Of fifty miles, but the telewriter
can be designed for use in connection
with any weil-insulated land wire, and
an apparatus IS actually being projected
10 transmit messages between London
and Paris for the service Of a daily
newspaper
A combined telewriter. transmitter and
receiver takes the form Of a cabinet about
twenty-one inches high and fifteen inches
broad The message is written with a
lead pencil upon a portion Of a paper
roll. and the writing is reproduced in
purple ink by means OF a pen al a dis
tant receiver The point OF the trans
mitting pencil is at the intersection Of
two iGiBted rods. and as the pencil IS
moved the end Of each rod communicates
a semi-rotaTy motion to each Of two
shafts Taking the case Of the simplest
possible written stroke. the purpose Of
the rod and shaft mechanism is 10 re-
solve the pencil movement into two
cOmpOnents, inverting in effect the prob
lem Of the parallelOgram Of forces. The
pencil point is free 10 move over a space
five inches wide and three inches deep
When the rods cause the rotation Of the
shafts. two electrical contact rollers be
meath the writing desk make Connec-
tiOns with pair Of p0tentiometers. which
vary the voltages n two electrical cir
cults The resistance Of these circuits
being kept constant 10 go 0hms, the cur
rents transmitted over the line are pro-
portionaI to the voltages.
Every Movement Recorded.
At the telewriter receiver each line cur
rent operates a moving coil. working in
the manner OF a galvanometer. which
transmits motion through shafts and
rods to the recording pen. Necessary
springs and other fittings are introduced
and so calibrated that the rotation OF
the shafts OF the moving coils synchron-
ize and correspond IN extent with those
Of the potentiometers. Thus every move
ment Of the pencil is reproduced with
faithful accuracy by the distant pen.
When the available writing space has
been filed, the paper is fed forward al
the transmitter mechanically on pulling
a lever somewhat similar 10 that Of a
typewriter. This lever at the same time
closes a circuit and sends a current
through both lines with an earth return,
and when the earth return is thus used
the current operates relay at the other
end and so actuates the paper fed OF
the receiver
In order to transmit electrical impulses
20 provide means for raising and lowering
the receiving pen to correspond with simi-
lar movements OF the transmitting pencil
a superimposed alternating current is
sent over the lines without interfering
with the direct currents which transmit
the written message The slightest pres
sure OF the operators pencil against the
platen ove- which the paper passe:
closes the circuit of the primary winding
OF an induction coil. SO that whenever
the pencil is on the paper the alternating
current induced in the secondary winding
is superimposed upon the writing cur
rents ard. by q suitable electro-mechsn-
ism, presses the receiving pen upon the
paper. To prevent disturbance IN neigh
boring circuits the alternating current IS
confined 10 the lines by means OF a con-
densor and a choke coil. The receiving
{ pen When not in use repOses in an ink
well and also takes up 2 fresh supply Of
( Ink every time the paper feed is operated
Has Telephone Attachment.
In practice the teIewriter Is fitted wstE
telephone attachments. and communities
/ lion can be obtained both orally and II
writing, but not simultaneously. The
writer OF the message has the exclusive
use OF the lines for the tine being. and
| u there hapeRs 70 be an observer at ths
receiver who wishes &c interrupt ths