At the beginning there was only the runner carrying messages, but in 1837 the invention of the Morse code opened up completely new possibilities for transmitting a message: over wire lines with telegraphs or wirelessly with light or sound. The telephone was not added until 1888, but for a long time it played a completely subordinate role to telegraphy. The first experiments with "sparks" took place in 1905. Devices for this were only purchased in very small numbers up until 1933 (maximum: 24 units of the portable heavy station in 1918). Unfortunately, the Mat Mag does not have any of these devices. Therefore, the following categories differ from those of eras 2 to 4.