Plane diffraction grating with 14

Plane diffraction grating with 14,438 lines per inch ruled on Rowland's engine at Johns Hopkins University on a plate prepared at the Astronomical and Physical Instrument Works of J.A. Brashear at Allegheny in 1890, on oxidised brass mount with circular rack and pinion for rotating grating, and three levelling screws

Details

Category:
Optics
Object Number:
1996-305
Materials:
brass (alloy), glass and metal
Measurements:
grating: 35 x 45 mm
brass mount: 120 x 110 mm
type:
diffraction grating - reflection
credit:
Epsom College