Astro-Camera 220 and Duetron double eyepiece
Astronomy
camera
optical instruments
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 focusing back, and extension tube. A air-shutter release, 30 mm f.l. eyepiece and instructions missing. Sold for $69.50 in 1954. Manual online at http://geogdata.csun.edu/~voltaire/classics/unitron/astrocamera220.pdf.
The Duetron double eyepiece sold for $23.40 in 1954.
It was donated to the University by Mrs. Ruth Scott of Chrisman Illinois in 1971 and valued at $70.
Unitron, Bohemia, New York
Info on line at http://www.company7.com/library/unitron/unitron_astro_camera.html
Astronomy Department, University of Illinois
circa 1953
Michael Svec
Copyright, Michael Svec
image/jpg
English
physical object
University of Illinois Observatory collection A238
University of Illinois Observatory, Urbana, Illinois
Eyepieces
Astronomy
Optical instrument
Telescope
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 ¼-inch right angle with off-axis guide, 12 eyepieces of various magnifications.
Warner & Swasey, JW Fecker
Astronomy Department, University of Illinois, Urbana, Illinois
circa 1896
Michael Svec
Copyright Michael Svec
image/jpg
English
physical object
University of Illinois Observatory Collection A103, A104
obs823
University of Illinois Observatory, Urbana, Illinois
Photoelectric photometer filters
Astronomy
Optical instrument
Photometry
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).
Unknown
Astronomy Department, University of Illinois, Urbana, Illinois
circa 1917
Michael Svec
Copyright Michael Svec
image/jpg
English
physical object
University of Illinois Observatory Collection A210
University of Illinois Observatory, Urbana, Illinois
Heliostat foucault
Astronomy
Optical instrument
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 fixed telescope, a flat mirror is rotated by a lever arm connected to motor turning once every 24 hours. James Biddle of Philadelphia imported these instruments.
Societe Genevoise D’instruments de physcique (SIP), Geneva, Switzerland
Prix-courant 1900 / Société Genevoise pour la construction d'instruments de physique et de mécanique, Chemin Gourgas, Genève (1900) Genève : W. Kündig & Fils. Page 86.
Astronomy Department, University of Illinois, Urbana, Illinois
1910
Michael Svec
Copyright Michael Svec
image/jpg
English
physical object
University of Illinois Observatory Collection A209
University ID 055343
University of Illinois Observatory, Urbana, Illinois
Plate camera
Astronomy
Photography
Camera
Optical instrument
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 film. There is an off axis guider that accepts 0.69” eyepieces and the plate carrier can be rotated by 180 degrees. There are two lateral screws (90 degrees apart) that can be used for tracking by moving the film instead of the telescope. The instrument is still located in the Observatory and is usable.
In the 1950s and 1960s it was used for instruction. There are approximately 270 plates from this time period in the Astronomy Department.
Images include the envelope, calibration plate, and image of the Moon taken on February 21, 1975 by Jim Wehmer. The glass plates were Kodak 103a-E film. The original plates are in the possession of Jim Wehmer and are shared here with his permission.
Warner & Swasey Company
Astronomy Department, University of Illinois, Urbana, Illinois
1896
Michael Svec
Copyright by Michael Svec
image/jpg
English
physical object
University of Illinois Observatory Collection A106
University of Illinois Observatory, Urbana, Illinois
Visual spectroscope
Astronomy
Measuring instrument
Optical instrument
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 of position of the emission or absorption lines to an accuracy of 6.5 Angstroms with the prism and 3 Angstroms with the diffraction grating. Slow motion arm is damaged, soldering makes attaching to the stand difficult.
In Stebbins’ notebook, “One second size astronomical spectroscope with circle and slow motions, one 1-inch grating, one dense flint prism with minimum deviation, without micrometer. Final bill June 29 $200.”
“The curves are based upon the normal solar spectrum produced by a small grating spectroscope attached to the 12-inch refractor. The center of the sun’s image was kept on the slit of the spectroscope, . . . The spectroscope is a modest affair, being next to the smallest size regularly manufactured by Brashear. The ruled surface of the plane grating is 19 x 25 mm and the objectives of the collimator and view telescope are each of 19 mm aperture and 285 mm focal length.”
Cleaned by J.W. Fecker in 1954.
John Brashear, Pittsburgh
Stebbins, J. 1907. The color sensibility of selenium cells. Astrophysical Journal. 26, 326, 183-187.
John A. Brashear Company LTD. (1906). Catalogue: Optical, physical, astrophysical and astronomical instruments. John A. Brashear Co. LTD.: Allegheny PA.
Astronomy Department, University of Illinois, Urbana, Illinois
1907
Michael Svec
copyright by Michael Svec.
image/jpg
English
physical object
University of Illinois Observatory Collection A132
University ID 016671, obs67
University of Illinois Observatory, Urbana, Illinois
Filar micrometer
Astronomy
Measuring instrument
Optical instrument
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 position circle 6.3 inches in diameter, graduated on silver to half degrees and read by to verniers to tenths of a degree and a very accurately threaded screw, carrying a light frame holding the micrometer wires. Whole revolutions of the screw are read by a toothed wheel and fractional parts of the screw are given by a drum of 2.5 inches diameter whose circumference is graduated to hundredths. Tenths of divisions are readily estimated. The micrometer box is moveable in position angle, the entire system of threads fixed and movable is carried ‘in distance’ by a screw without graduations and the eye piece is adjusted to the center of the fields by a still different screw.”
A filar micrometer is used for precision positional astronomy by measuring the separation or angular distance between two objects. In addition it can measure the position angle between them. They were often used to measure the angles and distances between double stars. Data gathered over long periods of time could demonstrate the orbit of one star about the other star. Micrometers are seldom used on modern astronomy having been replaced by newer techniques.
This micrometer came with the Equatorial. Stebbins used it to measure size of crater Linné during February 8, 1906 lunar eclipse. Cleaned by J.W. Fecker in 1954.
Warner & Swasey Company
Myers, G.W. (1898) The Astronomical Observatory. Technograph. 11: 105-111.
Stebbins, J. (1906) Observations of the crater Linné during the lunar eclipse of February 8, 1906. Astronomical Journal. Vol. 25. No 587, p. 87-88.
Astronomy Department, University of Illinois, Urbana, Illinois
1896
Michael Svec
Copyright Michael Svec
image/jpg
English
physical object
University of Illinois Observatory Collection A102
University ID 016717, obs 735
University of Illinois Observatory, Urbana, Illinois
Visual polarizing photometer
Astronomy
Measuring instrument
Optical instrument
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 magnitudes. It is used on double stars where one of the stars has a known magnitude.
“The polarizing photometer used in these observations was constructed by Alvan Clark & Sons. It is of the form devised by Professor Pickering and described by him in Annals of Harvard College Observatory, Vol.11, page 4, where it is designated as ‘Photometer H’. A Wollaston prism forms two images of each star, and these images are varied in intensity by rotating a Nichol placed between the eye and the eyepiece. . . This instrument is capable of extremely accurate results, bit its use is limited to those stars which are closer than about 100”"
Used by Stebbins to observe double stars in 1904-06 and Delta Cephei in 1907 leading to pioneering work by on measuring brightness using electricity making visual photometry obsolete. After Stebbins left in 1922 with the photoelectric photometer, C.C. Wylie resumed using the visual photometer to study WW Aurigae and Delta Cephei. It was used in the 1950s and early 1960s for instruction after a cleaning by J.W. Fecker in 1954. In 1957 Robert Tull and in 1961 Robert Roeder prepared instructions on the photometer’s use.
Alvan Clark & Sons
Stebbins, J. (1907, July) Photometric observations of Double stars. The University Studies, vol, 2, no. 5. University of Illinois Press.
Stebbins, J. (1908). The light-curve of δ Cephei. Astrophysical Journal, 27, 188-193.
Wylie, C.C. (1925). Note on the eclipsing variable WW Aurigae. Popular Astronomy, 33:600-601.
Report of observatories. (1924). University of Illinois Observatory. Popular Astronomy. 32:98-99.
Astronomy Department, University of Illinois, Urbana, Illinois
1899
Michael Svec
copyrighted by Michael Svec.
image/jpg
English
physical object
University of Illinois Observatory Collection A131
University ID 016670, obs 66
University of Illinois Observatory, Urbana, Illinois