Telegraph – 2/13/09 class paper

What were the specific technical issues referring to wire and resistance, that presented the early telegraph to be wired directly, coast to coast. What solution finally worked? Illustrate how that works, allowing coast to coast telegraph communication.

The longer the wires, the more resistance they have. More resistance – less current flows. The usage of thicker wires or higher voltage lowers the resistance but it still was limited to a couple hundred of miles.
The solution was a relay station; that uses electromagnet as a switch, which, activates by current and resends the message further (by an amplified current).

Telegraph