The telegraph manual: a complete history and description of the semaphoric, electric and magnetic telegraphs of Europe, Asia, Africa, and America, ancient and modern.

BAIN'S PRINTING TELEGRAPH.
CHAPTER XVII.
DESCRIPTION OF THE PRINTING TELEGRAPH APPARATUS.
ON an examination of English authorities for the preparation
of this work, I have been very often surprised to find the many
ingenious contrivances invented by lMr. Alexander Bain. He
was not a commercial man, but his inventive powers were
most wonderful. He has given to the world some invaluable
inventions in various departments of the sciences and arts.
As early as 1840, [Mr. Bain was active in the production of
a printing telegraph, of which full accounts are to be found in
the various publications. I present the following as a description of his printing apparatus:
The figure overleaf exhibits the arrangements of M1r. Bain's
telegraph. Imagine two figures the same, one representing
the Portsmouth, and the other the London station. The same
letters will refer to either instrument: d, i and h represent the
signal dials, insulated from the machine. x is a hand or
pointer. The small dots represent twelve holes in the dial,
corresponding with the twelve signals, and two blanks, 1, 2, 3,
4, 5, 6, 7, 8, 9, 0. u is a similar hole over the starting point
of the hand, x. R is a coil of wire, freely suspended on centres.
K K is a compound permanent magnget placed within the
coil, and immovably fixed upon the frame of the machine. J
and J are sections of similar permanent magnets. s is a spiral
spring (and there is another on the opposite side) which conveys the electric current to the wire coil, and at the same time
leaves the coil free to move in obedience to the magnetic influence. So long as the electricity is passing, the wire coil continues to be deflected, but the instant the electric current is
broken, the springs, s, bring back the coil to its naturCal
position. L is an arm fixed to and carried by the wire coil,
R and R, to stop the rotation of the machinery. B is a main
spring barrel, acting on the train of wheels, G, n and I, which
communicate motion to the governor, iv, and the hand, x.
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