SALMOIRAGHI

 La Filotecnica was founded in 1865 by Ignazio Porro ( 1801 – 1875), the inventor of the prismatic binocular. Porro served in the Italian Army before retiring with the rank of major, in 1842. He worked in Paris for about fifteen years, producing a variety of surveying and optical instruments before returning to Italy in 1861. He founded the Officina Filotecnica at first in Turin and then, in about 1865, in Milan. The factory combined production with what we would probably call nowadays a school for apprentices. Porro seems to have had a poor head for business and in 1870 one of his pupils, Angelo Salmoiraghi (1848 – 1939), took over the ownership of the business after a short period in management. Under Salmoiraghi as La Filotecnica Salmoiraghi,  the firm became one of Italy’s leading producers of optical and precision instruments. In 1877 start the production of the first italian sewing machine.Today, the firm, trading as Salmoiraghi e Vigano, manufacturers principally spectacles and markets optical goods made by other firms.   

http://www.storiadellafotografia.it/2012/04/30/filotecnica-salmoiraghi/#more-5221

http://sextantbook.com/2010/10/05/a-fine-sextant-by-filotecnica-salmoirhagi-of-milan/