Selection of six Nicol prisms (cemented composite crystal of Iceland spar - calcite), unsigned, supplied by James Swift and Son Limited, London, England, 1900-1936. Six Nicol prism polarisers 1900-1936
differential ratio polariscope by Negretti and Zambra, London, type devised by J. J. Field in 1869. fitted with a large Nicol prism 1 1/4"x2 1/2", with analysing prism and descriptive pamphlet Differential ratio polariscope by Negretti and Zambra, with rotating prism
Set of 12 Nicol prisms in case by E. Lutz, Paris, c. 1876. Set of 12 Nicol prisms in case by E. Lutz 1870-1876
Patent projective microscope by Newton & Co., London, c.1887. Fitted with 5-inch condenser, front lens with rack work, polarising prism and arm, convergent systems, iron lined body made for electric or limelight rotating-divided stage and analyser, also substage condensers nos. 2 & 5, in wooden case. The accessories comprises 4 objectives 1/4 undulation and Klein's quartz plates, adjustable slit, 4 diaphragms, additional condensers, adapting tubes etc. Patent projective microscope by Newton & Co. 1885-1890