John Stancliffe manufactured instruments between 1779 and 1812, initially from 26 Little Marylebone St, Cavendish Square and then from 1793 at another address in Little Marylebone. He worked for Jesse Ramsden whose famous division engine had revolutionised octant and sextant production with highly accurate scales. Many other manufactureres paid him to produce scales for their instruments and the various anchor marks will be familiar to collectors. After observing Ramsdens engine Stancliffe built his own, completeing in in 1788, and set up a business making sextants. The lot offered is a high quality product with advanced features [such as the vernier magnifier and light enhancer] which only became standard fifty or more years later. Of particular interest is the unusual technique of engraving a scale directly on to an arc instead of the usual method of insetting a scale of bone or precious metal, it is also between and third and a quarter the size of an average contemporary instrument and together with the ingenious compact case mark it out as an expensive instrument of very high quality.