Zeiss Dipping Refractometer

Description:

Zeiss Dipping Refractometer,Carl Zeiss, Jena, No. 8835, with vulcanite-covered tube, black enamel and nickel-plated finish, calibrated eyepiece with linear scale 0-100, and micrometer wheel, lg. 15 in., in maker's fitted case with thermometer in tube and additional prism in case.

Note: Originally introduced by Carl Zeiss in 1899, the dipping refractometer was mainly used for determining the concentration of solutions, for example in the sugar industry. It also found an application with acids, since only the glass prism dips into the solution.
Estimate $200-300