Zeměměřické a astronomické přístroje používané na území ČR od 16. do konce 20. století
Ignazio Porro as an Italian artillery officer has contributed to numerous improvements in surveying instruments. In 1839, he named his mapping device a tacheometer. In 1842 he retired and established a workshop in Turin and in 1847, in Paris, he founded the Institut technomatique. Based on the prisms, bearing his name, he made a monocular telescope . In 1863 he became a professor of technology in Milan, and founded the company Tecnomasio italiano, which in 1865 became Filotecnica. From 1871, Angelo Samoiraghi took the lead; the company name was later changed to Filotecnica Salmoiraghi. Until 1975, the company was producing geodetic, topographic and photogrammetric instruments and planimeters.
