Cased Reflecting Circle signed Troughton

An outstanding example of a Reflecting Circle by Edward Troughton, one of the foremost scientific instrument makers from the late 18th century into the early 19th. This instrument is signed Troughton, London No. 125, placing its manufacture between roughly 1805 and 1810.

The reflecting circle is a classic navigational tool designed for celestial observation, used to calculate a vessel’s longitude at sea. Its great advantage over the sextant lay in its fully graduated 360-degree arc, which allowed multiple successive readings and delivered superior accuracy—particularly important for the demanding lunar distance method.