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

THE FRENCH TELEGRAPH BELL INSTRUMENTS. 347
around K. Behind the other plate, c D, as seen in fig. 2, is
the electromagnet E E, of which the wire is attached to
two binding-posts, in connection with two exterior screw or
binding posts.
Fig. 1.,4Y,''-i
1^1- I1%!? ~]''''1 I
One of the screw posts connects with the line, by which the
current is to arrive, and the other with the earth. The armature, Ai Ai', is moveable around AI'. Its rod, M' n' m, moves between two screws, limiting its course. The recoil-spring is
tightened by means of the screw n. A little strip, Pi o' rn,
drawn down by the spring o o', presses upon the upper part of
the armature-rod, and descends when the armature is attracted
by the electro-magnet.' The axis p,, which traverses the two plates, is invariably fixed
to the rod P o' in, and to the quoin Pi, fig. 1. It turns when
the rod p1 o' m, fig. 2, descends. One of the sides of the quoin
n i