DESCRIPTION OF THE AMERICAN ELECTRO MAGNETIC TELEGRAPH. PAGE. Introduction, 7 The Galvanic Battery, 9 The Wire, 13 The Electro Magnet, 13 The Register, 18 The Correspondent, 22 The two Dependent Circuits, 23 The two Independent Circuits, 24 The operation of the Electro Magnetic Telegraph, 25 The Telegraphic Alphabet, 27 Specimen of the Telegraphic Language, 28 Telegraphic Alphabets for two, three, four, five, and six pens, operating together, or in succession, 30 Correspondent or Key, 32 The Lever Key, 40 The Circuit of the Electro Magnet, closed and broken by the movement of the Lever itself, acted upon by the Electro Magnet. Showing the rapidity with which it is possible to close and break the Circuit, 41 Conducting Power and Galvanic action of the Earth, 43 Six Independent Circuits, with Six Wires, each wire making an Independent Line of Communication, 44 Mode of Secret Correspondence, 46 Experiments made with 100 pairs of Grove’s Battery, passing through 160 miles of insulated wire, 53 The Galvanometer or Galvanoscope, 57 An Interesting Experiment of supporting a Large Bar of Iron within the Helix, 59 Application of the Electro Magnetic Telegraph to the Determination of Longitude, 59 Mode of Crossing Broad Rivers, or other Bodies of Water Without Wires, 60 Telegraphic Chess Playing, 63 Improvement in the Magneto Electric Machine, and Application of this Instrument to operate the Magnetic Telegraph, 65 REPORTS OF CONGRESS ON THE SUBJECT OF ELECTRO MAGNETIC TELEGRAPHS.