direct-vision spectroscope
Date: 1870-1880
Inventory Number: 2006-1-0120
Classification: Spectroscope
Subject:
Maker: William Augustus Rogers ? (1832 - 1898)
Cultural Region:
Place of Origin:
Dimensions:
6.8 × 5.2 × 21 cm (2 11/16 × 2 1/16 × 8 1/4 in.)
DescriptionThis is a home-made or shop-built direct vision spectroscope. It consists of a wood box painted black, with an adjustable slit at one end, a movable lens in the middle, and a transmission grating at the other end.
The front end of the box has an adjustable slit formed by two brass plates with adjacent knife edges. The top plate pivots on a screw and pushes against a spring. Above this plate is a brass lever that forces the plate down towards the lower one, thus decreasing the slit width.
A lens is mounted inside the box on a frame that can be moved forward or backward by means of a knob in a slot in the top of the box. The knob is made from a convex-headed screw.
The rear end of the box (closest to the eye) has a transmission grating ruled on a glass slip held between two glass slides. The slides are taped together on the edges. Two pieces of black-cloth tape at the top and bottom of the grating assembly are held by means of two small screws to the oblique end of the box. A thin brass plate, painted black and pierced with a round window, is held down over the grating with the same two screws.
The front end of the box has an adjustable slit formed by two brass plates with adjacent knife edges. The top plate pivots on a screw and pushes against a spring. Above this plate is a brass lever that forces the plate down towards the lower one, thus decreasing the slit width.
A lens is mounted inside the box on a frame that can be moved forward or backward by means of a knob in a slot in the top of the box. The knob is made from a convex-headed screw.
The rear end of the box (closest to the eye) has a transmission grating ruled on a glass slip held between two glass slides. The slides are taped together on the edges. Two pieces of black-cloth tape at the top and bottom of the grating assembly are held by means of two small screws to the oblique end of the box. A thin brass plate, painted black and pierced with a round window, is held down over the grating with the same two screws.
Signedunsigned
Historical AttributesThis is a shop-built or homemade direct vision spectroscope. It is an early use of a transmission grating and likely the work of a local scientist.