constant deviation spectrometer
Date: 1925-1935
Inventory Number: 1997-1-0074
Classification: Spectrometer
Dimensions:38.5 × 34 × 36.7 cm (15 3/16 × 13 3/8 × 14 7/16 in.)
Description:
This instrument is made of two optical tubes: one has an adjustable slit (from which light would enter the instrument) and the other is a telescope. Inside the casing is a prism (perhaps of the Pellin Broca type) that most likely rests on a rotating platform. This rotating system is linked to the outside graduated circle, which has four different scales. Both prism and circle rotate with the help of the front knob located under the telescope. An arrow-pointer, fixed to a spring and pulley, moves sideways from one scale to the other. There is a small electric lamp on the side of the casing. The instrument is supported by a telescoping stand on a tripod.