12-inch equatorial refractor
Astronomy
Optical instrument
Telescope
Measuring instrument
The telescope is a refractor with an objective of 12.4 inches clear aperture and of 15 ft. focal length. The objective is by J.A. Brashear of Allegheny, the curves used being those of Professor Charles Hasting. The objective is a doublet, or achromatic lens. Brashear used postage stamps to separate the two elements. The cell did have a small plate saying “J.A. Brashear, Allegheny Pa.” Brashear-Hasting objectives had the flint in front design. Flint is not typically the front lens because it was thought to be more susceptible to atmospheric attack and scratches. Hastings showed otherwise.
The telescope has a German equatorial mount on a rectangular cast-iron column of two-tons weight. The polar and declination axis are cylinders of steel three-inches in diameter. The tube consists of seven cylinders riveted together, six of 2.5 ft length and the seventh somewhat shorter. The sheets of steel composing the cylinders are 1/16 to 3/32 inches thick.
Two large graduated circles help with positioning the instrument. The right ascension wheel is 18.1 inches in diameter, graduated to 5 minutes. The declination wheel is 30 inches diameter graduated to single degrees for the same purpose in declination. The graduation marks of these coarse circles are streaks of white paint on a black back ground and are easily legible from the eye end of the tube in any position of the instrument. There exists a vernier scale for the right ascension but it is not longer operational. The vernier scale in declination is still operational and read from the eyepiece end of the telescope through 2 brass tubes. On the eyepiece of the declination reading telescope is marked "Gundlach Optical Rockchester NY."
The instrument is further provided with a driving clock. The original was replaced in the 1954 with a motor driving drive. Slow motion in both right ascension and declination was achieved by hand turned knobs at the eyepiece end of the telescope. Currently they are operated by electric motors. Right ascension and declination clamps are brought to the eyepiece. On the north side of the pier is a sidereal dial (clock work missing) and a wheel for coarse motion in right ascension.
The helioscope or finding telescope is 3.2 inches aperture and 4.5 ft. focal length, also by John A. Brashear. It has a brass tube and accepts 1 ¼ inch eyepieces.
The telescope came with a filar micrometer (see below), 6 negative eyepieces, 1 zenith prism, 1 helioscope (finder) and the plate camera (see below). Added 8 weights and bracket in fall 1911, also worked on the worm. According to Warner & Swasey, it was designated M-42, two other telescopes of this type were sold to Dudley Observatory in New York and American University in Beirut, Syria. The Dudley Observatory telescope is currently in storage.
The telescope was assembled in November 1896. In a March 6, 1897 letter to President Draper, director G.W. Myers noted “The equatorial room, not having been finished on the interior, the unpainted interior surface of the wooden dome is continually exposed to the moisture of the air, which causes the dome to become deformed so seriously during damp weather as to make it well nigh impossible to mange it for several days thereafter. The open condition of the room also contributes seriously to the difficulty. Under present conditions, the $5000 equatorial must necessarily injure rapidly from exposure. Half a dozen times since the instrument was mounted last Nov. a sheet of ice chrystals [sic] has formed over the lens from the excessive moisture of the room, so thick as to render observations temporarily impossible. This condition of things must injure the lens in time if not obviated.” Money was appropriated to paint and caulk the room.
“When the writer (Joel Stebbins) took charge of this Observatory in 1903, he found that the 12-inch objective had not given satisfaction for some years. The out of focus image were elliptical, and with good seeing the definition was rather poor. However, the lens was far from useless, and it seemed best to go ahead with the program of double stars, most of which were easy objects for an instrument of this size. During the summer of 1905, the writer was to be absent from the Observatory, and the lens was shipped to Allegheny at the request of Mr. Brashear, who naturally became interested when he learned that an objective of his manufacture was not giving satisfaction. He found that the metal ring which holds the lenses in the cell had been pressed down on one side, and allowed to remain, causing a permanent bending, principally of the flint lens. Although he was in no way responsible for this occurrence, Mr. Brashear kindly refigured both lenses without cost to the Observatory, and the objective was returned in October 1905. The defects were corrected, and now we have a first class objective.”
The telescope was restored in 1953 by J.W. Fecker Inc. for $15,000. The telescope was disassembled about April 10, 1953 and sent to Pittsburgh. It was returned later that summer using a better quality crane than the one used to remove the telescope. At that time, the gravity driven drive, the manual slow motion controls, the right ascension vernier scales, and the right ascension friction wheels were removed and the telescope was updated with electric motors. The dome motor was also replaced. In the late 1980s, members of the astronomy club cleaned the recent paint off the telescopes’ brass tail piece and improved the telescopes’ electronics.
The telescope was restored for a second time during the summer of 2013 by Ray Museum Studios of Swarthmore, Pa.
Warner & Swasey Company, Cleveland, Ohio and
John Brashear, Allegheny, Pennsylvania.
Stebbins, J. Photometric Observations of Double Stars. The University Studies. Vol. 2, no. 5. July 1907. University of Illinois Press.
Myers, G.W. (1898) The Astronomical Observatory. Technograph. 11: 105-111.
Astronomy Department, University of Illinois, Urbana, Illinois
1896
Michael Svec
copyrighted by Michael Svec
image/jpg
English
physical object
University of Illinois Observatory collection A101, A105
University of Illinois Observatory, Urbana, Illinois
2-day Marine Chronometer
Astronomy
Clocks
Mahogany wood, brass, silver, glass
Chronometer of 56-hour duration is set in gimbals in a mahogany box. Serial number #2805. John Bliss and Company was active 1857-1956.
Marine chronometer within wood box with hinged lid measuring 7-inches by 7-inches by 7-inches. Includes a label with University of Illinois in script. A pendulum clock would not work well on an ocean vessel. Knowing the time to within a second was critical for marine vessels to determine their position and navigate. A 19th century marine chronometer used a balance wheel to regulate the time. In addition they were gimbaled within the box to counter the movement of the ship.
A photograph from Oct 5, 1957 shows a box chronometer sitting next to radio receiving equipment that was being used to track Sputnik. Unknown which chronometer but it shows that at least one existed until 1957. Stebbins listed as worth $50 in 1908.
John Bliss & Company, New York
Harvard has an example, serial number 2620 dates 1880s at http://waywiser.fas.harvard.edu/objects/2763/56hour-marine-chronometer
Astronomy Department, University of Illinois, Urbana, Il
Circa 1885
Michael Svec
copyright Michael Svec
English
physical object
University of Illinois Observatory Collection A128
University of Illinois Observatory, Urbana, Illinois
2-inch altitude-azimuth universal telescope
Astronomy
Navigation
Surveying
Measuring instrument
Optical instrument
Wood, metal, glass
Stored in 2 large wooden boxes (22 ¼ x 12 ½ x 14 ¼ and 22 x 22 ½ x 17 inches). Transit consists of base with three leveling screws, telescope, striding level, 3 eyepieces, several lens caps for the eye pieces and an objective light shield. Silver vernier scales are tarnished, brass reading microscopes and micrometers are pitted in places, black paint on telescope tube also pitted. Three spirit levels on base (two perpendicular to telescope one parallel) all functional. Inscribed “Troughton and Simms London” on the support for the horizontal tangent screw and “obs 62” on base by the reading microscope A.
Myers’ description of the instrument: "This instrument was made by Troughton and Simms, has an aperture of 2-inches and a focal length of 20-inches. Its horizontal and vertical circles are each 12-inches in diameter, graduated on silver to 5 minutes and read by two reading microscopes to single seconds. Tenths of seconds are readily estimated. It is provided with both fine and coarse levels for adjustment to place, an accurate striding level, and a very complete set of eyepieces. The reticle consists of nine vertical and three horizontal cross hairs, illuminated by a lamp at the end of the axis. Both vertical and horizontal circles shift for position, this instrument being the first to have a shifting vertical and among the first to have a shifting horizontal circle."
Article describing the theodolite from 1882: “A theodolite, constructed by Troughton & Simms, of London, at a cost of about $700, has been added to the equipment of the Civil Engineering Department. It is an ‘Altitude and Azimuth’ or ‘Universal’ instrument; that is, both vertical and horizontal angles can be read with it. It is the finest and best form of the most accurate engineering instrument that has, as yet been made, having all the most modern improvements. The two circles - the most important part of the instrument - are twelve-inches in diameter and graduated to five-minute divisions. Upon each, the further reading is effected by the help of two micrometers and verniers, directly to seconds; each circle may be shifted between sets of observations, and by thus reading the angle on different parts of it, any error in the graduation is thus eliminated. The telescope is superior to either of the two now in the Observatory. It was intended to mount the theodolite permanently in the Observatory with the other instruments, but the manufacturers have send a tripod, and now the instrument may be used at any point desired.
“The money, with which to buy this instrument, was appropriated in 1871, but when taxes were abated in Chicago, after the fire, the appropriation for the new building was cut off, and this money was used in its place. In 1873, another appropriation was made, but for some reason the matter was dropped until last May, when a third appropriation was made. In July an order for the instrument was send to London, and it was completed and shipped about January 1, of this year. The theodolite is to be used in the classes in Geodesy and Practical Astronomy."
This instrument was used to observe the December 6, 1882 transit of Venus across the Sun.
A 1954 survey of the instruments by J.W. Fecker Inc. noted “This instrument is in poor condition as a result of extreme neglect and many small parts appear to be missing. The considerable expense involved in reconditioning this unit might be inadvisable unless an immediate need existed for the instrument. We suggest that no reconditioning be undertaken in the absence of such need. We do recommend that the instrument be carefully reconditioned as to finish only by interested and capable students and then used temporarily as an exhibit item in the observatory entrance foyer.”
Troughton & Simms, London
Myers, G.W. (1898) The Astronomical Observatory. Technograph. 11: 105-111.
The New Theodolite. April 1, 1882, The Illini, p. 10.
Transit of Venus. December 9, 1882. The Illini, p. 8.
Astronomy Department, University of Illinois, Urbana, Illinois
1883
Michael Svec
Copyright Michael Svec
image/jpg
English
physical object
University of Illinois Observatory Collection A113
University ID 016648, obs 62
University of Illinois Observatory, Urbana, Illinois
24 ft Dome and transit house shutter tracings
Astronomy
Architecture
Three tracings by Warner and Swasey for the University of Illinois.
1) 24 ft. Dome section, tracing B2860, dated April 21, 1896. Stamped with "University of Illinois Observatory."
2) 24 ft. Dome and 12-in Equatorial General Dimensions, tracing B-2859, dated April 20, 1896.Stamped with "University of Illinois Observatory."
3) Transit house shutter, tracing B-2883, Job 6351, dated May 1, 1896. Purchased by Astronomy Department in 1986.
Warner & Swasey, Cleveland Ohio
Astronomy Department, University of Illinois, Urbana
1896
Michael Svec
Copyright, Michael Svec
image/jpg
English
Document
University of Illinois Observatory, Urbana, Illinois
3-inch combined transit and zenith telescope
Astronomy
Optical instrument
Measuring instrument
Navigation
Surveying
Metal, glass
The principle transit circle was a 3-inch Combined Transit and Zenith telescope designed by Warner & Swasey especially for Illinois. The objective, by John Brashear, was held in place by a special cell that compensated for the different temperature conductivities of the brass and glass so that temperature had no effect on the location or separation of the lenses. Designated as model M-505, the transit includes a handing level, micrometer with a reticle contained a series of 5-3-5-3-5 parallel lines etched onto glass, and a built in reversing mechanism. This transit was located in the east-central transit room allowing direct access to the clock room through a small window. A basin of mercury (mercury now removed) in the base of the transit was used for vertical collimation and nadir observations. Marked with a Warner & Swasey plaque and a smaller J.W. Fecker plate added after the April-June 1953 restoration.
The transit circle was capable of determining both right ascension and declination. Installed February 20th 1897 and dismounted in 1974 because of the condition of the roof and shutter. The instrument cost $1200, and was the first of five 3" combined transit and zenith telescopes. Additional M-505 were built for Park College (1897), Warner & Swasey Observatory at Case Western Reserve University (1898), Lafayette College in Easton PA (1906) and the Elgin Watch Company in Illinois (1909). The Park College telescope was stolen in the late 1980s and the observatory no longer exists. The Traill Observatory at Lafayette College was torn down in 1929 and Warner & Swasey Observatory in Cleveland is abandoned. The transit was featured in Warner and Swasey’s 1900 portfolio “A Few Astronomical Instruments.”
Myers’ description of the instrument: "The combined transit and zenith telescope has a Brashear objective of three inches diameter and a focal length of 37 inches. It has two graduated circles, one of 12.5 inches diameter, graduated to half degrees and read by verniers to minutes, and the other of 12 inches diameter, graduated to 10 minutes and read by verniers to 10 seconds. Delicate striding and zenith telescope levels, together with a micrometer that may be used either in right ascension or declination render the instrument capable of yielding very excellent data whether used as a transit instrument or as a zenith telescope.
“The larger part of the weight of the horizontal axis, which by reason of its system of circles, levels, etc., is subject to considerable flexure, is borne by a pair of friction rollers, held by springs against cylindrical bearings at either end and about 2 ½-inches within the pivots. Only enough weight is allowed to come upon the pivots to make them rest firmly in the wyes.
“By suitable combination consisting of a level, a graduated circle and a reversing apparatus the west pivot may be brought into the east wye and the instrument reset upon the same star with extreme quickness and perfect safety. In addition to the above mentioned facilities, the instrument is supplied with a mercurial horizon, a complete set of eye pieces, including a collimating and a zenith eye piece. All in all, this instrument leaves little to be desired in either point of convenience or of completeness."
One of Warner & Swasey’s most important achievements was the construction of a Dividing Engine in 1880 for automatically graduating circles of 40-inch or less in diameter. The greatest errors made by this machine were less than one second or arc. This instrument was used to make the vernier scales for all of their telescopes and transit telescopes including both the Illinois transit and equatorial. Warner & Swasey built a 6-inch transit circle for the U.S. Naval Observatory in 1898 and remained a premier astrometry instrument for almost a century.
C.M. Huffer remembered using the transit in the course Practical Astronomy about 1916 for the determination of time and position. Astronomy club president F. Samuel Bauer remembers that in 1962 "Equinoxes were a special time for students, in that they were celebrated by timing them. Using the transit instrument, an ad hoc group would fire up the shortwave radio in the timing room and get the ink flowing on the chronograph, with the WWV signal providing timing blips. Other members would use the transit telescope to time the passage of a chosen star to determine the exact time of the equinox sending 'wire crosses' to the chronograph pen by telegraph key."
Warner & Swasey Company
Warner & Swasey. (1900). A few astronomical instruments. From the works of Warner & Swasey, Cleveland, Ohio. Warner & Swasey: Cleveland.
Myers, G.W. (1898) The Astronomical Observatory. Technograph. 11: 105-111.
Astronomy Department, University of Illinois, Urbana, Illinois
1896
Michael Svec
Copyright Michael Svec
image/jpg
English
physical object
University of Illinois Observatory Collection, A110
University ID 016647
University of Illinois Observatory, Urbana, Illinois
30-inch mirror
Astronomy
Optical instrument
Telescope
Wood, metal, glass
Frustrated by the selenium cell photometer's lack of sensivity, Joel Stebbins purchased a large 30-inch reflector in 1912. The original telescope was purchased from C.W. Draper, $1500, #573, July 26 1912. It has previously been owned by Elmer Gates who used the telescope as a burning glass. According to Robert Baker: “The original telescope was made by the Brashear Company after the specifications of an individual whose plan was apparently not astronomical. According to one account he purposed using it as a burning glass for manufacturing diamonds. Another story is that he expected to observe the flight of souls. However this may be, the instrument was finally on the market at a very small price and my predecessor, Professor Joel Stebbins, recommended its purchase by the University. The telescope was quite unusual as its original purpose appears to have been. The 30-inch mirror had a focal length of only 20 inches and such necessarily imperfect definition that it was not the easiest matter to distinguish between a star and the moon.” A 1914 article in the Urbana Daily Courier states that the original mirror was by Brashear and was used in Washington DC as a huge burning glass, used to melt platinum.
Once in place, Stebbins and his assistant Elmer Dershem used the 30-inch telescope as a test bed for the selenium photometer as late as 1919. The photoelectric cell photometer being used in the main Observatory was proving to be very sensitive so the work on the selenium cell was eventually ended by the time Stebbins left Illinois in 1922.
Since the original Brashear mirror had proven unsatisfactory, a new mirror was ordered around 1925. The new primary mirror was 29 ½ inches in diameter, 4-inches thick with a 4-inch hole in the center. The missing secondary mirror was 7-inches in diameter. Both were made of borosilicate crown glass figured by John E. Mellish, an amateur telescope maker turned profession located outside of Wilmette Illinois around 1925. As an amateur he discovered six comets and is credited with being the first to see craters on Mars. The new focal length of the primary was 75-inches and the focal ratio of the Cassegrain system was 12.
The original mount from 1915 was an equatorial with a fork mounting. It was later adapted to the new 30-inch telescope in 1925 and to the Ross camera in 1939. The wooden dome was constructed in 1915 with a double slit.
With the new optics and longer focal length, the telescope mount needed to be modified. Six brass rods supported the secondary mirror in its new position. Focus was achieved by racking the secondary along the optic axis of the primary. Slow motion controls and clamps were added as were long counter-balance weight rods. The clock drive was also modified to handle the extra load. The 30-inch observatory's new site was on the south side of Florida Avenue, just east of Wright Street, about a quarter mile south of the Observatory. The site had darker skies courtesy of a cemetery to the north and crop fields to the south. The telescope was operational by December 1927. In 1938 Baker replaced the 30-inch mirror with a 4-inch Ross Fecker camera.
Currently on the Mellish 30-inch mirror remains. The mirror has lost the silver coating and has a 7-inch crack but test have shown it still retains it’s figure.
John Mellish
Baker, Robert H. "The 30-inch Reflecting Telescope and Photoelectric Photometer of the University of Illinois." Popular Astronomy. 122:86-91.
"University buys big telescope" (August 5 1914) Urbana Daily Courier, page 3.
Astronomy Department, University of Illinois, Urbana, Illinois
1927
Michael Svec
Copyright MIchael Svec
image/jpg
English
physical object
University of Illinois Observatory, Urbana, Illinois
4-inch reflector Celestar
Astronomy
Optical instrument
Telescope
Metal, glass, wood
Celestar telescope with fork-type mounting and electric drive. Includes wood tripod, slow motion adjustment both axes, right ascension and declination setting circles and achromatic 30 mm finder scope. A chain links the three legs. White and blue color metal tube houses a 4-inch f/8.75 mirror, Newtonian design. A few hundred of this model were made. It cost approximately $200 in 1954. Came with two 1 inch focal length eyepieces, a 1/3 inch focal length eyepiece and a achromatic Barlow lens. Serial number 456.
J.W. Fecker, Pittsburgh
Astronomy Department, University of Illinois, Urbana
circa 1956
Michael Svec
Copyright Michael Svec
image/jpg
English
physical object
University of Illinois Observatory
6-inch f/16 equatorial refractor by Jeslerski
Astronomy
Optical instrument
Telescope
Metal, brass, glass, wood
Donated by Mrs. Ruth Scott of Chrisman Illinois in 1971. Equipped with solar filter, diagonal, slow motion, 60 mm guide telescope, 25 and 50 mm finders, equatorial mount on heavy movable wooden tripod. Valued at $1,500 in 1971. Very little is known about Jeslerski (1888-1944) and few telescopes by him are documented. He was an ethnic German who immigrated from Poland to Chicago. He did advertise in Popular Astronomy in the 1930s. Matches a set of 4 eyepieces, right angle prism and Hershel wedge marked with the letters “TEJ.”
Theodore E. Jeslerski, Chicago, Illinois
Astronomy Department, University of Illinois, Urbana, Illinois
circa 1935
Michael Svec
Copyright Michael Svec
image/jpg
English
physical object
University of Illinois Observatory Collection A219
University of Illinois Observatory, Urbana, Illinois
Algol light curve
Astronomy
Photometry
Eclipsing binary star
Joel Stebbins used the selenium cell photometer to study the known variable star Algol. The improved accuracy of the photometer revealed the second minimum and the limb darkening.
Astrophysical Journal
Stebbins, Joel. (1910) The measurement of the light of stars with a selenium photometer, with an application to the variations of Algol. Astrophysical Journal, 32, 185-214.
http://adsabs.harvard.edu/abs/1910ApJ....32..185S
1910
English
document
University of Illinois Observatory, Urbana, Illinois
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