Babinet goniometer / refractometer

Ph & F Pellin, Paris
Brass circle (21 cm) with fixed collimator and rotatable telescope and central platform with vernier read-outs. Total height: 39 cm. This type of instrument, often called "Babinet’s goniometer", was originally designed for the measurement of interplanar angles and refractive indexes; it was used also for spectroscopic investigations.
Signed "Ph & F Pellin Paris", early 20th century (1912 or later).

collection: Museum for the History of Sciences, Universiteit Gent, Belgium (inventory number: MW 98/2925)