The telegraph was the first device of the telecommunications age.
Although it seems quite primitive now, at the time the telegraph was the wonder of its age because it used the new sciences of electricity and electromagnetism to send information over long distances in the blink of an eye.
The telegraph key is simply a switch in an electric circuit that turns on an electric current.
As the sender taps out a word the switch completes a circuit which ...
Electricity needs a continuous path for the current to flow along, and it won't flow if the path is broken. This path - the electric circuit - needs a voltage from a battery or an electrical generator to push the ...
One of the facts of life is that nothing's perfect. There is no such thing as a perfect cable, where everything you put in comes out at the other end. In real life, a cable has resistance and there are stray electrical ...