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

448 THE MORSE TELEGRAPH APPARATUSES.
passes through the register magnets, which causes the pen
lever to mark upon the paper. If the magnetism in the cores
be too strong, the armature D is drawn farther from their ends
by the adjusting screw o, to the end of which is attached a silk
thread or cord. This cord is tied to one end of a spiral spring,
N, the other end being fastened to the armature lever. These
explanations are, I presume, sufficient to enable the reader to
understand the application of the relay magnet in the telegraph
apparatus.