Refractometers and related instruments

Abbe refractometer (black lacquered and nickel plated brass) on blackened cast iron base. Rotatable glass hemisphere with graduated circle and mirror. Movable telescope connected to a graduated circle with vernier read-out.
Height 33 cm, base diameter 15 cm.
Signed on the graduated circle "R. | FUESS | BERLIN-STEGLITZ" and serial number "5929", ca. 1954.
With a 7 page instruction booklet, dated 1954 (15 x 21.1 cm).

Abbe refractometer (black lacquered and nickel plated brass) on blackened cast iron base. Rotatable glass hemisphere (central hole for illumination from the bottom) with graduated circle (and vernier read-out) and mirror. Elbow shaped movable telescope connected to a graduated circle with vernier read-out. The telescope houses a slider with a Nicol analyzer, and a hinged magnifying lens in front of the eyepiece to transform it to a low-power microscope. Height 32 cm, vertical circle diameter 15 cm.
Signed on the graduated circle "DR. CARL LEISS BERLIN-STEGLITZ " on the vertical circle. Inventory numbers as IVd81 (scratched on the triangular base of the collimator) and 36049 (written with white paint on a tripod foot).

Brass and black painted cast iron Pulfrich type refractometer (height 30 cm, circle diameter 12 cm).
Unsigned, but made by Max Wolz, Bonn, late 19th century.

Lacquered brass circle of Jamin and Sénarmont for the determination of angles and refractive indexes and for the study of the polarization of reflected light on metallic and crystalline substances and on liquids.
The circle (diameter 26 cm) may be oriented either horizontally or vertically. The small circles (diameter 11 cm) with alidades and vernier read-out accommodate the analyzer and polarizer. The instrument (total height 45 cm) was designed to accommodate a number of accessories described in the catalogue of Ph. Pellin (Fascicule IV) and in a paper of Jamin (Annales de Chimie et de Physique, 3e série, tome XXIX, juillet 1850)
This instrument misses most of the original optical parts and the accessories.
Signed "J. Duboscq à Paris", 2nd half 19th century.

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).

Gem refractometer, lacquered and black lacquered brass, 7.8 x 4.2 cm, signed "J.H. STEWARD | LONDON" and numbered "212". In original wooden case, 10.3 cm x 5.5 cm height 7.2 cm.
First half 20th century.

Set of different instruments in glass fronted wooden cabinet (lacquered black, 30.2 x 22.6 x 13.2 cm). The items include: microscope (lacquered and black lacquered brass, height 27 cm) signed on the base "J.H. STEWARD. LONDON." with two specimen holders; bull's eye condenser lens (lacquered brass); tweezers; refractometer (lacquered and black lacquered brass, 7.8 x 4.2 cm), signed "J.H. STEWARD | LONDON" and numbered "267"; dichroscope (lacquered and black lacquered brass, tube length 6.4 cm, diameter 1.1 cm), signed "J.H. STEWARD | LONDON"; separate compartment with mahogany box with glass bottles containing heavy liquids (methylene iodide etc.); stone tester (three hardness points and gauge) nickel plated brass, with instruction leaflet (12.8 x 7.3 cm).
First half 20th century.

Simplified immersion Kohlrausch total reflectometer (brass, nickel plated brass and blackened triangular cast iron base).
The upper part carries a divided circle (9cm diameter) with vernier and a lateral read out lens. The axis of the graduated circle ends with a crystal holder which may be immersed in a liquid contained in a detachable glass flask (here broken). The observation telescope is horizontally disposed in a collar of the vertical column.
Signed "R. Fuess Berlin-Steglitz". Old inventory numbers IVd83, 1473 and much recent 36050 (written with white paint on the base). ca. 1900.