Description

A cased brass sighting level by Andreas Boehme dated 1797. Made for establishing horizontal measures by hanging the instrument on a line, these were used in surveying and mining and were sometimes affixed to instruments such as the graphometer or theodolite to establish level planarity.  Contained within original case with makers signature and stamps, original plumb bob with historic thread, and fine patina, the instrument features the typical German punched numbering of the 18th century.

Andreas Boehm is mentioned by Marice Daumas as a professor at Giessen who constructed scientific instruments. He is author of the 1807 publication Gründliche Anleitung zur Meßkunst auf dem Felde (Thorough instructions for the art of measuring in the field) where he clearly illustrated this sighting level on plate 12 (see last image). Boehme is mentioned in the 1776 “Liste des astronomes Connus…”by Bernoulli and appears in the 1767 L’Esprit des journaux franc̜ais et étrangers – Volume 59 as having provided a work by Tycho Brahe to a French astronomer.