SMALL ENGLISH LACQUERED BRASS MINERALOGICAL POLARISCOPE
07-030. English, 4th quarter 19th century, unsigned. Made of polished lacquered brass and standing 12" (min), extending to 13 3/4" with rack & pinion coarse focussing. A 9 3/4" tall triangular microscope-type column is mounted on the heavy black painted cast iron base, with a 1 3/4" diameter single-sided concave mirror at the bottom of the column, a simple stage containing the Nicol prism polarizer & condensing lens above the mirror, a condensing lens above the stage, and the Nicol prism analyzer at the top, with a goniometer for measuring axial angles. Also included is a cork-mounted thin section specimen of "turmalin" by Dr. F. Krantz for use with the instrument. This rare mineralogical polarization apparatus is in very good overall condition, with most of its original lacquer finish, in a very good fitted mahogany case.
