Telegraph
Title
Telegraph
Subject
Electricity
Description
The telegraph was invented by the artist and scientist Samuel Finley Breese Morse (1791-1872), who conceived the idea of the printing telegraph during an ocean voyage to Europe in 1832. The actuation of an electromagnet in the receiver would cause a pencil to make marks on a continuously-moving strip of paper. The first instrument was made in 1836, and improved after Morse contacted Joseph Henry. The use of the relay to allow the signal to be retransmitted to increase the range was invented by Morse, Henry, Wheatstone and Siemens. The first long-distance line was constructed between Washington and Baltimore with the assistance of federal funds, and the first message sent May 24, 1844. Printing or recording receivers similar to the one in the picture at the left, below, were originally used. This improved model, dating from the 1870s, used a clockwork mechanism to pull a long strip of paper past a sharp point which was pushed into the paper by the electromagnet. Early on, the operators learned to distinguish the long and short sounds as the electromagnet clicked in and out, and relied almost exclusively on the sound, writing down the letters of the message by hand. This version was sold by James W. Queen of Philadelphia at a relatively hefty price of $50.00.
Source
Property of the W&L Physics & Engineering Department
Files
