Introduction.

The galvanic battery.

The wire.

The electro magnet.

Alphabet.

Specimen of the telegraphic language.

Correspondent or key.

The lever key.

The circuit of the electro magnet, closed and broken by the movement of the lever itself, acted upon

Conducting power and galvanic action of the earth.

Six independent circuits, with six wires, each wire making an independent line of communication.

Mode of secret correspondence.

The galvanometer or galvanoscope.

An interesting experiment of supporting a large bar of iron within the helix. discovered by mr. vail

Application of the electro magnetic telegraph to the determination of longitude.

Mode of crossing broad rivers, or other bodies of water, without wires.

Telegraphic chess playing

First game of chess.

Second game.

Improvement in the magneto electric machine, and application of this instrument to operate the magne

Reports to congress on the subject of electro magnetic telegraphs.

Employing electricity in various ways for the transmission of intelligence.

Lomond’s electrical telegraph.

Reizen’s electric spark telegraph.

Dr. salva’s electric spark telegraph.

Origin of galvanism.

The decomposition of water.

Samuel thomas soemmering’s description of his voltaic electric telegraph, invented in 1809.

Extract from the journal of the franklin institute, vol. 20, page 325.

Ronald’s electric telegraph, invented in 1816.

Electro magnetism.

The following extract is taken from a work on electro magnetism published by jacob green, m. d. prof

Triboaillet’s proposition.

Fechner’s suggestion.[22]

Magneto electricity.

Dr. page’s magneto electric machine.

The pole changer.

Schilling electric telegraph.

[27] the electro magnetic telegraph, of counsellor gauss and professor william weber, invented at gö

Experiment of messrs. taquin & ettieyhausen.[28]

Electro magnetic printing telegraph, invented by alfred vail, september, 1837.

Steinheil’s electric telegraph.

Masson’s electric telegraph.

Davy’s needle and lamp telegraph.

Alexander’s electric telegraph, from the (scotsmen) mechanic’s magazine, nov. 1837.

Extract from the report of the academy of industry, in reference to a suggestion of m. amyot of an e

Bain’s printing telegraph.

Wheatstone’s rotating disc telegraph, invented, 1841.