Apocromat 16mm brass case with screw cap, containing a copper and brass microscope objective lens with aperture 0.95, and written note dated 19/2/1982, Carl Zeiss, Jena, Germany; Plastic case, containing a copper and steel microscope objective lens with aperture 1.40, Carl Zeiss, Jena, Germany; Microscope objective lens inscribed ‘1 1”/2 NAO. 197’, C Baker, London, England; Copper and brass microscope objective lens with aperture 0.95, Carl Zeiss, Jena, Germany; Brass microscope lens case with screw cap, labelled ‘Zircon FRONT N.A. 1.92’, containing written note dated 21/1/1962, unsigned; Black metal case with silver screw cap, containing a brass microscope objective lens hand inscribed with ‘H Dall 1957’; Orange plastic case, containing a copper and brass microscope objective lens with aperture 0.95, Carl Zeiss, Jena, Germany; all part of a collection of optical instruments used by Horace Dall