Prism Spectroscope

This fine spectroscope is a prism type, giving a brilliant spectrum of ample length and sharpness suitable for the use in observing the solar spectrum, observing and charting flame spectra, and in the absorption mode testing authenticity of valuable gems.

The collimator and the telescope objectives have 18 mm apertures and a focal length of about 200 mm. The telescope has focal adjustment and rotates about the prism axis to permit settings on any part of the spectrum. The scale for measuring wavelengths is mounted on a draw tube to permit adjustment of its focus.  It is a photographic transparent negative having 22 figured divisions each divided to tenths. The two sodium lines are easily resolved in this spectroscope. The prism table cover, for protecting the prism and lenses from dust, is enameled black and held onto the table with knurled brass thumb screws. The slit is adjusted through a spring linkage to protect the jaws.

The spectroscope stand is a black cast iron base with three legs. The prism table is aluminum and brass. The telescope, collimator and back lighted scale tubes are brass gold lacquered . The prismís back surface is painted black. The overall condition is very good. Cosmetically it has a few paint chips and some spotting of the lacquered brass. The unit is unsigned.  The most likely manufacture date is late 1800.  AST Item #463  .

Overview with prism cover off

Telescope and wavelength tube Adjustments
Prism and its table
Entrance slit
Wavelength Scale

Antiques of Science and Technology

Jim & Rhoda Morris

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