Telegraphy has three elements: a transmitter, a receiver, and a conducting medium.
In landline (cable) telegraphy, the originating message is encoded at the transmitter in the Morse code using a system of interrupted electric current. The receiver detects the series of interruptions and, via an electromagnet, converts them to audible clicks that reflect the coded message. The operator then translates the click patterns to Morse code equivalents and then to the original message.
Landline telegraphy relies on wire (cable) to carry the pulsed electric signals, a method limited by the distance and terrain cable can cover.
Acknowledgement Letter (826K)
Count V. Macchi de Celere to George A. Hoadley,
Acknowledging the award to Senator Marconi,
agreeing to accept on his behalf, 4/11/1918.
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Notification Letter (818K)