Some
Telegraphic Machines
with independent signals
Annales Telegraphiques,
vol. 4, no. 1, January-February, 1877
Translated by Eric Fischer
The telegraph administration is having Mr. Dumoulin-Froment construct
a multiple printer with quintuple transmission, of my invention,
relying on combinations of emissions of current at defined intervals.
Before entering into a detailed description of this telegraph, I
intend to review the machines preceding the one I invented and that,
like it, form their signals by means of determined combinations of
emissions of current.
I will leave aside those like the dial and the Hughes, in which the
signals are produced by equal currents of which the number and the
spacing are variable and depend on the preceding signal. The
remainder can be divided into two categories: first, those in which
time is not used to modify the effect of the current and does not,
therefore, intervene as an element of combination; and second, those
in which the effects of the current differ with the length or the time
of emission.
[Descriptions of predecessors not translated.]
In all the machines that have just been described and that belong to
the second category, the letters are formed by means of conventional
signals needing a translation. I invented a machine that only needs a
single wire and that translates the combinations of currents received
into typographic characters (patented June 17, 1874).
Here's what this machine consists of. The manipulator is formed of
six keys relayed to six contacts on a distributor, over which a brush
relayed to the line glides with a uniform motion. In the receiver, a
brush, similar to the one in the transmitter, puts the line
successively into contact with the six contacts of a distributor
relayed to six electromagnets. These reproduce, in the receiver, the
63 combinations that can be made by the keys of the transmitter. The
functioning of the six electromagnets determines the displacement of a
typewheel. The first makes it turn one division, the second two
divisions, the third four, the fourth eight, the fifth sixteen, and
the sixth thirty-two.
As in one of the Highton machines (1st disposition) and in the
Wheatstone translator, the various combinations of these movements
permit bringing the chosen character under a strip of paper. The
impression is made automatically; then everything returns to the idle
position.
The two operations that exact the reception of a character (that is to
say, first, the preparation of the signal for the functioning of the
framework, and, second, the rotation of the typewheel and the
impression) are made successively, and, the second being entirely
local, it is natural to put the line in contact with other receivers
while this latter operation is in progress. In this fashion, no time
is wasted. It is thus that my machine is found to be a multiple
printer.
I do not intend to describe here the machine in detail, nor the
numerous modifications to which I have subjected it. I will say only
that around the month of July, 1874, I invented a part which I have
since named the combiner. It is a modification of this part that
constitutes the principle piece of my current machine, of which the
description will be the object of a future article.
E. BAUDOT
Employee at the central station