Case for brass framed sextant.
Wooden case for Sextant by J.R. Martin
Brass sextant with two-plate frame, attached by 47 screws with wooden handle and fitted wooden keystone case with textile lining, by Joshua Lover Martin, London, England, 1775-1782. Consists of polished brass 122° scale (-5° to 125°) with vernier (1’), three index-filter shades (red, green & orange), two horizon filters (orange. Fitted with threaded bracket for sighting telescope (129mm – erect image & 160 – inverted image) and sighting pinhole vane.
Wooden case for Sextant by J.R. Martin
Sextant made by Joshua Lover Martin, London, late 18th century.