Prism and Lens Making: A Text Book for Optical Glassworkers

abrasive accuracy accurately Adam Hilger adjustment Angle Dekkor annealing temperature aperture apparatus astigmatism balsam bands block of lenses Canada balsam carborundum cemented centre chuck clean colour concave convex cooling corundum Dennis Taylor described diameter disc emery film flat focus forming tool fringes glass surface grades grain grinding ground heat inch instrument interferometer lamp lens light Lord Rayleigh mallet pitch material measured mercury metal method microscope minutes mirror Newton's rings nitric acid object glass observed optical glass optical tool optician paraffin wax piece of glass polished surface polisher polisher holder polishing machine position powder produced proof plate putty putty powder radius of curvature reflected refractive index refractometer removed ring roof prisms rotated rouge roughing rubbing scratches screw shape shown in Fig silver smoothing soft spherical spherometer spindle stroke telescope test plate thickness trueing tool Twyman viscosity warm wavelength workshop