MISCELLANEOUS METHODS.
“It never rains but it pours.”
Almost simultaneously with the demonstration of the
Morse telegraph other types were devised. There
were the needle systems of Cooke and Wheatstone, the
chemical telegraph of Alexander Bain, and soon the
printing telegraph of House, and later that of Hughes.
The latter is in use on the continent of Europe, and
a modification of it has a very limited use on some
American lines. The Bain telegraph used a key
and battery the same as the Morse system, but it did
not depend upon electromagnetism as the Morse system
does. When in operation a strip of paper was
made to move under an iron stylus at the receiving-end
of the line. The paper was saturated with some
chemical that would discolor by the electrolytic action
of the current. When a message was sent the paper
was set to moving by a clock mechanism or otherwise,
under the stylus that was pressing on the paper as
it passed over a metal roller or bed-plate. The
transmitting-operator worked his key precisely as
in sending an ordinary message by the Morse system.
The effect was to send currents through the receiving-stylus
chopped into long or short marks, or the dots and dashes
of the Morse code, and recorded on the tape in marks
that were blue or brown, according to the chemical
used. A few lines were established in this country
on the Bain system, but it never came into general
use.
A number of systems, called “automatic,”
grew out of the Bain system. Bain himself devised,
perhaps, the first automatic telegraph. The fundamental
principle of all automatic telegraphs depends upon
the preparation of the message before sending, and
is usually punched in a strip of paper and then run
through between rollers that allow the stylus to ride
on the paper and drop through the holes that represent
the dots and lines of the Morse alphabet. Every
time the stylus drops through a hole in the paper
it makes electrical contact and sends a current, long
or short, according to the length of the hole.
The object of the automatic system was to send a large
amount of business through a single wire in a short
time. It does not save operators, as the messages
have to be prepared for transmission, and then translated
at the receiving-end and put into ordinary writing
for delivery.
The automatic system is not used except
for special purposes, and the one that seems to be
the most favored is that of Wheatstone. The system
is in use in England and in America to a limited degree.
Early in the history of the telegraph
a printing system was devised. Wheatstone and
others had proposed systems of printing telegraphs
in Europe, but these never passed the experimental
stage. The first printing telegraph introduced
in America was invented by Royal E. House of Vermont,
and first introduced in 1847 on a line between Cincinnati
and Jeffersonville, a distance of 150 miles. In
1849 a line for commercial use was established between
New York and Philadelphia, and for some years following
many lines were equipped with the House printing telegraph
instrument. The late General Anson Stager was
a House operator at one time. All printing telegraph
instruments, while differing greatly in detail, have
certain things in common, to wit: a means for
bringing the type into position, an inking device,
a printing mechanism, a paper feed, and a means for
bringing the type-wheels into unison. There are
two general types of printing instruments, the step-by-step,
and the synchronously moving type-wheels. The
House printer was a step-by-step instrument and consisted
of two parts, a transmitter and a receiver. The
transmitter consists of a keyboard like a piano, with
twenty-eight keys. These keys are held in position
by springs. Under the keys is a cylinder having
twenty-eight pins on it corresponding to the twenty-six
letters of the alphabet and a dot and a space.
This cylinder was driven by some power. In those
days it was by man-power. It was carried by a
friction, so that it could be easily stopped by the
depression of any one of the keys that interfered with
one of the pins. One revolution of the cylinder
would break and close the current twenty-eight times,
making twenty-eight steps.
The receiving-instrument consisted
of a type-wheel and means for driving it. It
was somewhat complicated, and can only be described
in a general way. If the cylinder of the transmitter
was set to rotating it would break and close twenty-eight
times each revolution. (There were fourteen closes
and fourteen breaks, each break and each close of the
current representing a step.) The type-wheel of the
receiver was divided into twenty-eight parts, having
twenty-six letters and a dot and space, each break
moved it one step and each close a step; so that if
the cylinder, with its twenty-eight pins, started
in unison with the type-wheel, with its twenty-eight
letters and spaces, they would revolve in unison.
The keys were lettered, and if any one was depressed
the pin corresponding to it on the cylinder would
strike it and stop the rotation of the cylinder, which
stopped the breaking and closing of the circuit, which
in turn stopped the rotation of the type-wheel and
not only stopped it, but also put it in a position
so that the letter on the type-wheel corresponding
to the letter on the key that was depressed was opposite
the printing mechanism. The printing was done
on a strip of paper, which was carried forward one
space each time it printed. The printing mechanism
was so arranged that so long as the wheel continued
to rotate it was held from printing, but the moment
the type-wheel stopped it printed automatically.
The messages were delivered on strips
of paper as they came from the machine.
In 1855 David E. Hughes of Kentucky
patented a type-printing telegraph that employed a
different principle for rotating the type-wheel.
The electric current was used for printing the letters
and unifying the type-wheels with the transmitting-apparatus.
The transmitter, cylinder, and the type-wheel revolved
synchronously, or as nearly so as possible, and the
printing was done without stopping the type-wheel.
Whenever a letter was printed the type-wheel was corrected
if there was any lack of unison.
This type of machine in a greatly
improved form is still used on some of the Western
Union lines, especially between New York, Boston,
Philadelphia, and Washington. It is also in use
in one of its forms in most of the European countries.