Lunette Pyrometrique - "Pyrometric Telescope" Pyroscope Ducretet & Roger, Paris An optical instrument designed to observe or measure high temperatures, usually by viewing the thermal radiation emitted by hot objects. Commonly used in industrial settings, such as furnaces or kilns Rare optical instrument from late 1800s Slight pitting/marks on brass - otherwise in good overall condition The case is in pretty bad shape See pictures for condition
eBay