Dots and dashes
Morse and Alfred Vail devised a code in which the most common letters have the shortest signs. The letter E is a single dot. Experienced operators could recognise messages by sound alone, without writing them down.
The internet of the 19th century
Telegraph lines ran alongside railways and soon linked whole continents. In 1866 a transatlantic cable began working reliably, and a message from London to New York no longer took a week. Stock exchanges, newspapers and governments suddenly worked in real time.
Without wires
Towards the end of the century the telegraph learned to work without wires. The Slovak priest and inventor Jozef Murgaš also worked on developing wireless telegraphy. See also Radio.