The first sextant was produced by John Bird in 1759. This is a very early example of his work now in the Nederlands Scheepvaart Museum in Amsterdam. The frame is mahogany with an ivory scale.

When was the sextant first used?

The principle of the instrument was first implemented around 1731 by John Hadley (1682–1744) and Thomas Godfrey (1704–1749), but it was also found later in the unpublished writings of Isaac Newton (1643–1727).

Why was sextant invented?

Those promoting the use of lunar distances, or "lunars," for finding longitude at the end of the 18th century stimulated the invention of the sextant. The sextant was designed to find longitude by measuring the angular distance between the moon and a nearby star.