Model of an Optical Telegraph

Entry

Model of an optical telegraph, mounted on an octagonal pedestal.

This model consists of a shored mast with a short cross-beam at the top. Between two of the four shores, rungs are fitted for climbing the mast. Two wings attached halfway up the mast are operated with tackles that hang through sheaves at the top; two other signals, probably balls but now missing, can be raised or lowered by means of tackles going through sheaves at the ends of the cross-beam. The wings are mounted on a metal ring, which turns freely around the mast; by means of a pole, pushed from below, the wings can be turned to face another communication line.

This model was formerly numbered 1047. Obreen mentions two telegraphs from 1803 belonging to cabin models NG-MC-820 and NG-MC-822.¹ Although built to a different scale, the models described as numbers 819 and 821 are the only possible candidates; their identification, however, is uncertain.

The model is first mentioned as part of the private collection of Jochem Pietersz Asmus (1755-1837) in 1807.² This type of telegraph has not been found in other sources and was never used. It strongly resembles the telegraphs used for the coastal signal stations along the North Sea coast between 1798 and 1801, but could also be a proposed design of a later date, probably around 1803, when a new coastal telegraph line was planned.

The advantage of this design is the ability to turn the wings, which enables the telegraph to exchange signals with ships at sea along two perpendicular communication lines.

Scale (on model) 1:45.