Lehmann

A new type of telegraph, developed by Captain of the Engineers Wilhelm Otto Waldemar Lehmann (1817-94), was chosen for use in the new telegraph lines. The telegraph was basically a smaller version of Schumacher´s frame telegraph. In the years before the war, Lehmann had sat on a commission that discussed a modernisation of the optical telegraphs and introduced the new telegraphs between Halsskov and Knudshoved.

Sketch of Lehmann´s telegraph. The Danish National Archives.

The telegraph worked on the same principle as Schumacher´s, except that it only had two boards. This gave a total of 99 possible combinations. To increase the number of possibilities, Lehmann introduced two signals per sign: for the first one, the telegraphist looked up pages 1-99, for the second one he looked up numbers 1-99 on the page to discover the meaning of that number.

W. O. W. Lehmann.Photography. Post & Tele Museum.

Lehmann, who was appointed superintendent of the optical telegraphs during the Three Year War, was a mercurial character who quickly became embroiled in controversies in the press with, among others, supporters of the electric telegraph. A few years later, however, he himself supervised work on the setting up of the first electrical telegraph connection in Denmark.