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portarule

mechanical device

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development of telegraphy

  • White House Telegraph Room, 1898
    In telegraph: The first transmitters and receivers

    …incorporated a device called a portarule, which employed molded type with built-in dots and dashes. The type could be moved through a mechanism in such a manner that the dots and dashes would make and break the contact between the battery and the wire to the receiver. The receiver, or…

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Related Topics:
telegraph
fax

TelAutograph, short-line telegraph used to communicate handwriting and sketches. At the transmitter the motion of the pen or stylus traces out the material to be transmitted, and this motion is converted into electrical signals that are transmitted to the receiver. A pen or stylus at the receiver traces out the same motions as those of the transmitting pen, thus reproducing the writing or sketch. The TelAutograph was invented by Elisha Gray in the United States about 1895 and almost simultaneously in England by A.C. Cowper.

This article was most recently revised and updated by Robert Curley.