History of the Observatory:

Early Astronomy (1872-1896)

Astronomy was a science in transition during the 19th century. Classical astronomy focused on celestial mechanics and astrometry. It was intensely mathematical and sought to constantly improve precision and accuracy. Catalogs of stellar positions, parallax and proper motions were generated using the meridian circle, transit telescope, and zenith telescopes as their primary tools. The astronomer was first trained in mathematics. The change began in a physics laboratory when Robert Bunsen and Gustav Kirchhoff made it possible to analyze the chemical composition of stars using spectroscopy. Spectroscopy and photography began a shift away from classical positional astronomy toward physics. There was also a change from cataloging toward discovery. The new astronomy, astrophysics, would grow to dominate the 20th century.

Astronomy was first taught at the Illinois Industrial University in 1868, during the school's first year. Descriptive Astronomy consisted of lectures, use of Sir Norman Locker's Astronomy textbook and the application of practical astronomy by use of sextant, meridian circle and theodolite. Mathematics Professor Samuel Shattuck taught the course that was soon placed in the general curriculum, taken by juniors in their first semester. Early astronomy at Illinois was not taught by an astronomer and embraced the classical astronomy in order to satisfy the needs of the engineering students.

In 1872, the Department of Civil Engineering added a class, Practical Astronomy; all civil engineers were required to take this class to improve surveying skills. Surveying was an important skill for civil engineer students and a focus of their preparation. That same year three students pursued Descriptive Astronomy and two practiced Practical Astronomy.

In order to help facilitate the instruction of larger classes and to properly house the equipment required for Practical Astronomy, a small observatory was built during 1872. It was moved in 1875 to higher, drier ground south of University Hall. A note in the September 16, 1882 Illini notes;

“Our new observatory, situated to the southeast of the main building, is not a very elaborate one for an astronomical observatory, but is fitted more especially for the use of engineering students. Nevertheless it is much better than the old one, as it will contain two instruments instead of one” (p. 7).

The university attempted to add a universal theodolite several times during the early 1870s. Such a precision instrument was expensive and required a legislative appropriation. Unfortunately the loss of tax revenue in the aftermath of the 1871 Chicago fire prevented its purchase in 1871. Finally, for a price of $700 (approximately $15,000 in 2011 dollars), an altitude-azimuth instrument was purchased in 1882. The 1885 course catalog included the following description;

“A portable altitude and azimuth instrument of the latest and best form has lately been received from the celebrated makers, Troughton & Simms, of London. It is read by micrometer microscopes to single seconds, both of altitude and azimuth. This instrument will be used for instruction in Geodesy and Practical Astronomy.”(1)

The telescope arrival was announced in the April 1, 1882 Illini. The article noted “It is the finest and best form of the most accurate engineering instruments that has, as yet been made, having all the modern improvements . . . The telescope is the superior to either of the two now in the Observatory” (p.10). It was used later that year to observe the transit of Venus across the surface of the sun.

The University's Catalogue and Circular boasted the observatory was in constant use during favorable weather. The small-box shaped building was equipped with a 4-inch Newton & Company Equatorial refractor permanently mounted on a brick and stone pier. In addition, the observatory was equipped with a 1 ½ -inch Newton transit telescope with attachments for zenith observations, two sextants, chronometers, and the 2-inch Troughton & Simms theodolite, all imported from London. A complete set of meteorological instruments complemented the equipment. The students inPractical Astronomyused all the instruments, determining time, latitude and longitude.Descriptive Astronomystudents used the Equatorial for observations. Engineering professor Ira O. Baker frequently taught astronomy and one of his lessons on using the night sky as a clock was printed in the Illinois engineering magazine The Technograph.

The first campus observatory remained until October 1896 as construction on the new Observatory progressed. All the instruments were transferred to the new Astronomical Observatory where Illinois would begin to leave classical astronomy behind and embrace the new astrophysics.

Works cited

(1) Twelfth Report of the Board of Trustees of the Illinois Industrial University, for the two years ending September 30, 1884. Published Springfield: Rorker State Printer. 1885.

References

Baker, I.O. (1890). A clock for everybody. The Technograph. No. 5, p. 25-29.

J. Norman Lockyer. (1868) Elementary Lessons in Astronomy. Macmillan and Co.

Circular and Catalogue 1872-1873. Illinois Industrial University, Urbana: University of Illinois Archives.

Lankford, John. (1996) American Astronomy: Community, careers, and power 1859-1940. Chicago: University of Chicago Press.