A Victorian patinated brass sextant Potter, London, late 19th century The pierced 'ladder' pattern frame with pivoted arm mounted with mirror opposing hinged magnification lens over aperture for reading the fine silver inset brass Vernier scale signed Potter, Tower Hill & Poultry, London, with two sets of hinged filters, brass telescopic sighting tube and wooden grip to rear of frame, the fitted rectangular mahogany box with two additional sighting tubes and a telescope eyepiece slider, the inside of the lid with applied trade label ...HENRY HUGHES & SON, Optical, Nautical, Mathematical, Instrument Makers, 59 Fenchurch Street, London... the exterior with shaped brass name plate to lid, the box 26.5cm (10.5ins) wide. John Dennett Potter is recorded in Clifton, Gloria Directory of British Scientific Instrument Makers 1550-1851 as succeeding the role of Admiralty chart agent from the business of Thomas Brettell Bate from circa 1847. He worked in London from 31 Poultry 1851-82 and 11 King Street 1854-82 and was succeeded by his son Septimus C. Potter.