01 What is the Gauss-Weber telegraph?

First electromagnetic telegraph in the world – Georg-August-Universität Göttingen (uni-goettingen.de)

The Göttingen scholars Carl Friedrich Gauss and Wilhelm Eduard Weber built the world’s first electromagnetic telegraph, which they successfully tested in May 1833. The telegraph line, more than a kilometre long, ran across the roofs and towers of Göttingen from the then “Physical Cabinet” to the Göttingen Observatory. It thus connected the two scholars’ places of work and facilitated their communication in the context of their joint research into geomagnetism. The Gauss-Weber telegraph served as a model for the second electromagnetic telegraph, built by Carl August von Steinheil in Munich in 1837, which also sent and received messages over a long distance. With their invention, Gauss and Weber not only solved all the electrotechnical problems relevant to text transmission, but also – as the forerunner of Morse code (1847) and Emile Baudot’s telegraph code (1874) – developed the world’s first 5-bit telegraph code: “Know before mean, be before seem” was one of the first messages transmitted, the transmission of which took 270 seconds at the time.

The Gauss-Weber telegraph consisted of a transmitter, a line and a receiver. In the transmitter, which was located in the Physical Cabinet, a coil was pulled up and down by a lever on a long magnetic rod, producing short surges of electricity. These were transmitted via a wire line to the receiver in the New Observatory. There, the current was passed through another coil, causing a horizontally suspended magnetic rod to move slightly, which was clearly visible through the mirror and telescope. Depending on whether the induction coil at the transmitter was now moved up or down, the magnetic rod at the receiver swung to the right or left.

In order to be able to encode and decode a message from the sequence of these movements, Gauss and Weber agreed on a binary left-right code that defined letters and numbers as different sequences of four such left-right deflections each.