Instrument collection


Instrument collection


For most of human history, our eyes served as the recording device for our observations of the night sky. Later, developments in photography began to change how we viewed and documented astronomical observations. The instrument collection consists of auxiliary instruments used on the 12-inch equatorial refractor. Some of the instruments such as the filar micrometer and spectroscope were designed for use with human eye as the detector, others such as the plate camera used film.


Department of Astronomy

Collection Items

Visual polarizing photometer
Wood, brass, glass

Wooden box with hinged lid, barlow adapter, brass ring. Box measures 30” x 9” x 9”. The photometer is 24” long.

The visual photometer utilizes the polarizing properties of doubly-refracting crystals to measure stellar…

Filar micrometer
Wood, brass, glass

Wooden box (dimensions) with hinged lid, with 4 colored shades (2 green, 2 red), 3 eyepieces with adapter, one smaller eyepiece with adapter, accessories for light.

“Its filar position micrometer consists essentially of a…

Visual spectroscope
Wood, brass, glass

Comes with large wooden box with hinged lid (24” x 14” x 8”), 12”tall stand (obs 726), and accessories. It includes a dense flint prism and a reflection diffraction grating. Crosshairs and a precise scale permit the measurement…

Plate camera
Wood, brass

Wooden box (9 ½ x 9 ½ x 9) with hinge lid, two film holders, several 3-inch x 3-inch glass filters. The plate camera is an original piece of equipment made by Warner and Swasey. It takes 2 ¼-inch by 3 ¼-inch glass plates or sheets of…

Heliostat foucault
Metal, glass

Also Foucault siderostat. Marked “Societe Genevoise, pour la construction, D’instruments de physcique, Geneve.” Wind up drive does not work. Spirit level on black metal base with 3 leveling screws.

Siderostats are used with a…

Photoelectric photometer filters
Wood, metal, glass

Small wooden box (4 ¾ x 2 ¾ x 2”), 11 shades, some marked .66, .86, 1.31, 1.56, 1.80, 2.95, 4 unlabeled. Possibly 1917.

Made reference to use of shades in several papers including Nova Aquilae and Algol (1921).

Wood, brass, glass

Wooden box with hinged lid, spaces for 12 eyepieces. Includes 1 ¼-inch adapter, 2-inch adapter, 3-inch eyepiece (with cracked lens, visible in 1896 picture), 3-inch Fecker eyepiece with chipped lens, 2-inch right angle, 1…

Astro-Camera 220 and Duetron double eyepiece
Wooden box (9 ½ x 7 x 7) with hinge lid, three 2-sided film holders. It takes 2 ¼-inch by 3 ¼-inch glass plates or sheets of film. An air-operated shutter types speeds of 1/10 to 1/90 second in addition to bulb and time. Comes with ground-glass…
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