This folding viewer for individual stereoscopic pictures has a cut-out between the lenses to accommodate the nose of the user. The original folding viewer was patented by J. F. Mascher of Philadelphia in March 1853 and was designed to hold stereoscopic portraits using the daguerreotype process. This was at the very end of the daguerreotype era, and originals are quite rare.Metal stereo viewer and many cards including stereoscopic photographs of crystal modals (Bragg's Crystal, Fluorspar, caesieum chloride, zinc-blende, iron pyrites, quartz, Tellurirumetc), and Dr Mullers Universal X-Ray Spectrograph. stereoscope, adam hilger, sir william bragg, w.i. bragg, dr muller, x-ray, crystal, spinel, bismuth, diamond structure, tartaric acid, naphthalene

William Lawrence Bragg was born in Adelaide in 1890. Lawrence was only fifteen years old when he started study at the University of Adelaide. In 1908 he graduated with a first-class honours degree in mathematics. He worked as a professor of physics at the University of Manchester in 1919-1938 and at Cambridge in 1938-54. He shared the Nobel Prize in 1915 with his father, Sir William Henry Bragg at the age of twenty-five "for their services in the analysis of crystal structure by means of X-rays". He died in Waldringfield, England, 1 July 1971. Red hardcovered book with black and white illustrations. At the top of title "The Crystalline State Vol. IV". 409pp [inkstamped name on front free endpaper]. The book discusses the Crystal structures of minerals, by Sir L. Bragg and G. F. Claringbull, with a chapter by W.H. Taylor.metallic crystal structures, sir lawrence bragg, g f claringbull, physics