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

148 RONALDIS ELECTRIC TELEGRAPH.
or receiving station what letters to note down as they appeared
before him in succession on the dial of the clock.
Fig. 1
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This was accomplished in the following manner: The transmitter caused a current of electricity to be constantly operating
upon the electrometers, so as to separate the balls of those electrometers, except only when it was required to denote a letter,
and then he discharged the electricity from the wire, and instantly both balls collapsed. The distant observer was thereby
informed to note down the letter then visible. In this way
letter after letter could be denoted, words spelled, and intelligence
of any kind transmitted. All that was absolutely required for
this form of telegraph was, that the clocks should go isochronously during the timte that the intelligence was being transmitted; for it was easy enough, by a preconcerted arrangement
between the parties, and upon a given signal, for each party
to start their clocks at the same letter, and thus, if the clocks
went together during the transmission of the intelligence, the
proper letters would appear simultaneously, until the commu