This document discusses a sextant from 1792 that is in the collection of the National Maritime Museum in Greenwich. It provides details on the object, including that it was signed by the maker Jesse Ramsden in London. The document also discusses the manufacture of the sextant and Ramsden's dividing engine technique. Previous owners of the sextant are mentioned, including John Ommaney who served on a voyage to China in 1792-3, and Admiral Purey-Cust who eventually donated it to the museum. An interpretation of the sextant is also provided in one of the museum displays focusing on the invention of the sextant.