A RARE 18th century English ten sided single-draw Telescope by John Gilbert circa 1770

This rare signed scope was made by John Gilbert who worked from 1751 until his death in 1791. He was located at the Mariner, Postern Row, 7 Tower Hill, London. The spyglass measures 26" closed and 32 1/2" when fully extended. Very sharp and clear optics. The scope dates to circa 1760-1770.