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

PATENTED IMPROVEMENTS. 721
IT. IMPROVEMENT IN TELEGRAPHIC REGISTERS.
Patented January 29, 1856, by Moses G. Farmer.
The engraving shows the connection of the main circuits. A
represents the screw-cup which receives one main wire; the
course of the current is
through the main circuit
magnet m' to the anvil a,
spring s, and by wire w to A..
the screw-cup G, which is in -. 1 -a ~-E
connection with the ground. oP....
The cup B receives the other. -
main wire, and its course is a' I IZ.
through the magnet m to the'.y"" --.. -'-K- - -
anvil a', spring sl, by w', to.............
the ground G. The main /'...
circuit B will be opened by G. -
the movement of the armature lever of the local magnet L/; if L/ is charged, its armatures
will lift the spring s / from the anvil a', and thus break the
circuit B at that point. Similarly the circuit A can be broken at a
s by the motions of the armature lever of the local magnet L.
The inventor says: I am aware that a telegraphic register,
operating upon the same general principle as mine, has been
invented at an earlier date by Elisha Wilson, of New Haven,
Connecticut. In his machine, however, the local circuits are
both closed, while in mine the local circuits are similarly both
open when the main circuits are both closed. The same work
which in Wilson's machine is done by the closing of the local
circuit, is done in mine by the opening of the local circuit, and
vice versa. The general plan, therefore, in which my machine
agrees with Wilson's I do not claim; neither do I claim simply
substituting the breaking of the circuit for the closing to do the
same work.
But what I do claim is, that modified combination of parts
by which, in the self-acting telegraphic repeater, as described,
the breaking instead of the closing of the local circuit is made
to close the main circuit, and by which, throughout, the breaking of the local circuit is made a substitute for the closing.
III. IMPROVEMENTS IN PRINTING TELEGRAPHS.
Patented May 20, 1856, by David E. Hughes.
The nature of this invention will be understood from the
claims and the engravings.
The inventor says: I do not claim any feature of any exist46