The precursors: Pierre-Louis Guinand
Pierre-Louis Guinand, born to a family of watchmakers at Les Brenets in the Neuchâtel Jura, was extremely interested in the manufacture of optical glass, and from 1784 conducted research to obtain the best possible quality of “flint” glass. This glass was used for microscopes, telescopes, glasses and other optical instruments, and later in the manufacture of lenses.
His technique of mixing raw materials produced some exceptional results; subsequently called “guinandage”, this process was gradually introduced into all the glass factories, including that of Théodore Daguet in Solothurn, supplier to Lerebours and Secretan in Paris and Voigtländer in Braunschweig.
