Friedrich Gauß and Wilhelm Weber working at the first electrical needle-telegraph invented by themselves
Left Weber at the keyer apparatus which he uses to operate the electricity-converting solenoid; right Gauß at the receiver, watching the mirror of the galvanometer through a telescope. Inside the multiplicator solenoid below the mirror the magnetic needle, a heavy iron rod. The connecting wires are suspended over the city of Göttingen and also fixed at St. John's tower. After a drawing of A. Wald.
In the early summer of 1833, the first electromagnetic telegraph became operational in the city of Göttingen. It was conceived and built by physicists Carl Friedrich Gauß and Wilhelm Weber, and their assistants. It was Weber himself who climbed the buildings to lay the cables, which had a length of 5000 Lower Saxon Foot, about 1460 m, running between the institute of physics and the astronomical observatory.
Gauß wrote: "A wire connection has been established between the observatory and the physics cabinet; the total wire length is approximately 5,000 feet. Our Weber deserves credit for having strung these wires (across St. John's Tower and maternity house) entirely by himself. Almost countless times, the wires, once fully or partially finished, have been torn apart again (through mischief or accident). Finally, a few days ago, the connection appears to have been securely established; instead of the former fine copper wire, a somewhat stronger (varnished) iron wire has been used."
The keyer consisted of two contacts, which could generate a negative or positive electrical pulse. The receiver was a galvanometer, a early form of a moving coil meter, attached to a mirror, which had to be observed with a telescopic set of lenses. Gauß and Weber developed a code of positive and negative pulses for the letters of the alphabet, which allowed for a transmission rate of seven letters per minute. After the galvanometer was improved, 9 letters per minute were possible. The first reported message was: " WISSEN VOR MEINEN SEIN VOR SCHEINEN" (knowledge better than opinion, existence better than semblance).
Although the telegraph line existed until 1845, when it was damaged beyond repair by a lightning strike, it was not constantly in use. Wilhelm Weber was part of the Göttingen Seven and lost his professorship after protesting against King Ernest Augustus' anulment of the liberal constitution. Weber had to eke out a living as a private tutor and had little time to support Gauß, so the telegraph was only used temporarily. Weber regained his professorship after the March Revolution of 1848.
Gauß wrote about the destruction of the telegraph line: "The very strong lightning strike that struck St. John's Tower probably spread across these wires, destroying them all, breaking them into pieces, some larger, some smaller, pieces four to five inches long and countless small balls like poppy seeds, all forming a magnificent shower of fire. […] No damage was done, except that a lady's hat was burned by falling pieces of glowing wire, but it is very likely that the wires protected the tower, which offers no electrical conduction at all, and if ignited in the violent storm would perhaps have put the library and the town in great danger."
Here is the Gauß-Weber code in its two variants:
A: +++++ +
B: ++++- -
C: +++-+ ++
D: +++-- +-
E: ++-++ -+
F: ++-+- --
G: ++--+ +++
H: ++--- ++-
I: +-+++ +-+
K: +-++- +--
L: +-+-+ -++
M: +-+-- -+-
N: +--++ --+
O: +--+- ---
P: +---+ ++++
Q: +---- +++-
R: -++++ ++-+
S: -+++- ++--
T: -++-+ +-++
U: -++-- +-+-
V: -+-++ +--+
W: -+-+- +---
X: -+--+ -+++
Y: -+--- -++-
Z: --+++ -+-+
.: --++-
?: --+-+
/: --+--
Messages using the Gauß-Weber code are sent to the sky by laser during some events in Göttingen today. + and – are represented by long and short laser pulses, respectively.
