Year: 19??
Manufacturer: ??
Materials: aluminum, steel, brass, optical glass
Dimensions: L = 118; P = 65; H = 58
This compact instrument is designed to measure the magnitude of stars on photographic plates. A fixed diameter light beam passes through the plate and the light intensity is detected by a galvanometer.
By comparing the results with stars of known magnitude, it was possible to calculate the magnitude of unknown stars present on the plate. An essential instrument for astronomical photometry, combining precision and ease of use.