- Charles A. Young, the professor of astronomy at the College of New Jersey (later Princeton University), acquired this diffraction grating in 1878. The speculum metal plate measures 3 inches square overall, with the grating measuring 1.75 inch square. It is marked: "May 28, 1878" and "16,560 spaces" and "8648 per inch" and "Manf. by D. C. Chapman with Mr. Rutherfurd's Engine." Daniel C. Chapman was the mechanic who operated the ruling engine designed by Lewis M. Rutherfurd.
- Ref. D. J. Warner, "Lewis M. Rutherfurd: Pioneer Astronomical Photographer and Spectroscopist," Technology and Culture 12 (1971): 190-216.
- Currently not on view
- Object Name
- Diffraction Grating
- date made
- Rutherfurd, Lewis Morris
- place made
- United States: New York
- overall: 77 mm x 77 mm x 8 mm; 3 1/32 in x 3 1/32 in x 5/16 in
- overall: 4 in x 4 in x 1 in; 10.16 cm x 10.16 cm x 2.54 cm
- ID Number
- accession number
- catalog number
- Data Source
- National Museum of American History
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