, 1865-08-04
The Pantelepranh.

We have several times had occasion to
mention the Able Cassall's wonderful in
vention by which he not only transmits from
one place to another the words of dispatch,
but the very handwriting of the person who
sends it. As this new telegraph system is
now beginning to receive practical applica-
tion on large scale, a description Of the
apparatus may not be uninteresting to our
readers. Imagine a cast iron frame, shaped
like an A, and pendulum suspended from
its apex. AT each foot Of the frame there
is an electromagnetic, through the action Of
which, the Pendulum, which is two metres
in length, oscllates between them, accord
ing as an electric current passes from one to
the other. About the middle of the shaft
of the pendulum there is a sort of arm or
cam, which, at each oscillation, causes a lev
er fixed to the cross-bar Of the A, to des-
cribe circular arc At the end of this os-
oillation, this lever twice meets click and
spring g-work fixed to the same cross bar.
At the first stroke the metallic vibration
is interrupted, and at the second fork is
set in motion, the prongs of which alter
nately act on the teeth of ratch, which is
thus forced to turn, and in so doing commu-
nicates motion to an endless screw, cut into
its own shaft. This endless screw causes
two small chariots to move simultaneously );
each chariot carries fine steel point or sty-
lus Now, as in virtue of the endless screw,
these two points move uniformly in the
same direction-the progress of one not diff
fering from that of the other even by a
hairs breadth-it follows that whatever
stroke will be described by the one will be
initiated with mathematical exactness by
the other
Now, suppose metallic plate be placed
under each point, these plates being curved
like the circular arcs described by the points,
then after number of oscillations of the
pendulum, these points in moving along
will have described upon the plates as many
parallel lines infinitely close to each other as
there have been oscillations hence the
whole surface of the plate has been gone
over. The plates are in direct communica-
tion with the ground by means of chains /;
one of these plates we will call the trans
mitter, the other the recipient.
The sender of dispatch writes it with
common ink on a sheet of timed paper, and
places it on the transmitter. On the recip-
lent we place sheet of chemical paper, i'm
pregnated with a solution of cyanide of po-
tassium. Let us now set the apparatus in
motion. The current being established, so
long as the point of the transmitter only
touches upon the tin, the electric fluid will
escape into the earth; but no sooner does it
meet the ink of the writing, which is non
conductor, than the fluid, not finding an es-
cape there, will seek it along the wire which
connects the two points together.
Thus the point which works on the
chemical paper of the recipient will produce
blue stroke on the latter for every black
stroke on the dispatch for steel in contact
with cyanide of potassium, and under the
influence of positive current produces blue.
Hence, supposing the dispatch to have been
written in black in Paris, and transmitted
to Lyons, the correspondent at the latter
place will receive in blue the exact fac
sinaiLe of the sender's handwriting. An or
der to pay certain sum may thus be trans
mitted with perfect safety Galignani.