Electrical telegraphy is a point-to-point text messaging system, primarily used from the 1840s until the late 20th … See more

Prior to the electric telegraph, visual systems were used, including beacons, smoke signals, flag semaphore, and optical telegraphs for visual signals to communicate over distances of land.
An auditor… See more

The first commercial electrical telegraph was the Cooke and Wheatstone system. A demonstration four-needle system was installed on the Euston to Camden Town section of Robert Stephenson's London and Birmingha… See more

Main article § Section: History of longitude § Land surveying and telegraphy.
The telegraph was very important for sending time signals to determine longitude, providing greater accuracy than previously … See more

The ability to send telegrams brought obvious advantages to those conducting war. Secret messages were encoded, so interception alone would not be sufficient for the opposing side to gain an advantage. There wer… See more