This spectroscope, designed for use with an astronomical telescope, was given to Wesleyan University, in Hartford, Connecticut, in 1880. An inscription reads “IN MEMORIAM. DAVID H. WALKLEY, Graduated June 27th 1878. Died Sept. 15th 1878.”

The diffraction grating inside the spectroscope is inscribed “Ruled by Schneider on Rowland’s engine Johns Hopkins University 14,438 lines to the inch, 1887. Every hundredth line extended on one side, plate polished and corrected by J. A. Brashear Allegheny, Pa. U.S.A. 1887. Grade AE II Bright curve in 4th.” Henry Rowland, the first professor of physics at The Johns Hopkins University, built an engine for ruling the parallel lines needed for diffraction gratings. This engine became operational in March 1882, and Rowland gratings were soon in use around the world. In many instances, these gratings were on concave metal plates, figured and polished by John A. Brashear in Allegheny, then a suburb of Pittsburgh.

Ref: Alumni Record of Wesleyan University (Hartford, 1883), p. cviii.

Location: Currently not on view

See more items in: Medicine and Science: Physical Sciences, Science & Mathematics, Optics


Exhibition Location:

Credit Line: Wesleyan University

Data Source: National Museum of American History

Id Number: PH.328770Catalog Number: 328770Accession Number: 277481

Object Name: spectroscope

Physical Description: brass (overall material)Measurements: overall: 7 in x 18 in x 22 1/2 in; 17.78 cm x 45.72 cm x 57.15 cmoverall: eyepiece: 3 1/8 in x 4 1/2 in x 2 in; 7.9375 cm x 11.43 cm x 5.08 cmoverall: spectroscope: 6 7/8 in x 21 in x 17 5/8 in; 17.4625 cm x 53.34 cm x 44.7675 cm

Guid: http://n2t.net/ark:/65665/ng49ca746ae-0e31-704b-e053-15f76fa0b4fa

Record Id: nmah_1455925

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