Large reflector mirror

Reflector mirrors, known since Antiquity, had pride of place in galleries and cabinets of curiosities from the 17th century onwards. By concentrating the sun’s rays, they enable experiments requiring extremely high temperatures, such as the vitrification of earth or the melting metals and stones. In the 18th century the mastery of glassmaking techniques and Buffon’s research enabled the replacement of polished copper with glass to increase reflective power. This large copper reflector mirror is similar in workmanship to those made by François Villette (such as the one in the Observatoire de Paris) and by Ehrenfried Walther von Tschirnhaus (in the Royal Cabinet of Mathematical and Physical Instruments in Dresden). It was formerly in the cabinet of the scientist and inventor Jacques Alexandre César Charles.