Refractometer Optical Device in Case, by Zeiss

Instrument sits on a tripod base with a central round pillar. Instrument itself has a pillar with an arm holding a refracting prism. Attached via another arm on same pillar is an electrical cable. A rotating dial with gradated scale and Vernier holds a telescope above a wet cell which sits behind the refracting prism. A limb extends from instrument holding a lens with a movable metal shade. Instrument is screwed into a square wooden base.

Also present in case are three paper pamphlets marked with tables of refractor readings. Notes are written in German.

Instrument is stored in a wooden case with inbuilt runners which fit the instrument's wooden base. Case has a further wooden, felt lined accessory support on its door. Case has a metal handle and a key operated lock.

Box has a set of two keys both with a monogramed 'S' in their bows and fluted rings on their stems.