Man is the species on earth that is most characterized by the ability to communicate.
Since Ramses II sent four letter pigeons into all the world's directions to proclaim its coronation, man has availed himself of more and more refined aids to communicate over long distances and to turn to large masses of people. The railroad, introduced in the first half of the 1800 figure, made completely new demands for safe and verifiable communication over great distances in real time. A number of highlights from this development are reviewed.