<< >>
Usage conditions apply
Direct vision spectroscope inscribed “WALLACE / SPECTROSCOPE / CENTRAL SCIENTIFIC CO. / CHICAGO.” Instead of a prism assembly, this instrument has a replica diffraction grating of the sort developed by Robert James Wallace (1868-1945), a photographer at the Yerkes Observatory in Williams Bay, Wisconsin.
Ref: Robert J. Wallace, “Diffraction Grating Replicas,” Astrophysical Journal 22 (1905): 123-130, and 23 (1906): 96-99.
Central Scientific Company, Physical and Chemical Apparatus (Chicago, 1909), p. 234.
Currently not on view
Object Name
date made
early 20th century
Central Scientific Company
place made
United States: Illinois, Chicago
overall: 4 in; 10.16 cm
overall in housing: 3 11/16 in x 3 1/4 in x 6 7/16 in; 9.36625 cm x 8.255 cm x 16.35125 cm
ID Number
catalog number
accession number
Science & Scientific Instruments
See more items in
Medicine and Science: Physical Sciences
Science & Mathematics
Data Source
National Museum of American History
Nominate this object for photography.   

Our collection database is a work in progress. We may update this record based on further research and review. Learn more about our approach to sharing our collection online.

If you would like to know how you can use content on this page, see the Smithsonian's Terms of Use. If you need to request an image for publication or other use, please visit Rights and Reproductions.


A fine instrument. I have one of the first produced and it still functions as designed to this day. Robert Wallace referred to himself in a self made drawing/caricature as: “A lemon in a garden of love” While working at Yerkes Observatory in Williams Bay Wisconsin he was a fine creative photographer and designer of apparatuses.

Note: Comment submission is temporarily unavailable while we make improvements to the site. We apologize for the interruption. If you have a question relating to the museum's collections, please first check our Collections FAQ. If you require a personal response, please use our Contact page.