F3379

Newtonian secondary mirror Long Caption: An elliptical plane mirror made as a secondary mirror for a Newtonian reflector telescope. The diameter of the minor axis of this mirror is 33.02mm. This mirror has no mount but does have a brass backing with three screw holes and a cover marked 'No. 1'. Credit line: © National Maritime Museum, Greenwich, London, Herschel Collection Object: AST0814 Artist: Sir William Herschel Date: circa 1800 Medium: speculum metal; brass Size: diameter: 33 mm Click here to buy a bespoke print of this image.