Napoleon III Telescope (University of Notre Dame)

Lore & Background

The telescope was acquired in 1866 when Father J. C. Carrier of the University of Notre Dame was sent to France for a seven-month visit. He had an audience with Emperor Napoleon III, who had been a friend of Notre Dame's founder Father Edward Sorin and had an interest in science. Carrier returned with books, church ornaments, sacred vessels, and scientific instruments including the 6-inch refracting telescope, which was worth 25,000 francs and was one of a set built exclusively for the French government. The telescope was built at the Secretan Company of Paris, with construction supervised by Léon Foucault. The objective lens was reported to be 6 inches with a focal length of 9 feet, 9 inches, though Bro. Peter listed the focal length at 7 feet, 6 inches, which better matches photographs. The telescope was mounted on an alt-azimuth white walnut frame, with altitude controlled by gears and azimuth by chains. Inscribed in French on the tube was: 'Presented by his Imperial Majesty Napoleon III, to the Catholic University of Notre Dame du Lac, Indiana, United States.'

The telescope was stored in a classroom until a permanent observatory was completed in 1870, a small building with a revolving roof of 18-feet diameter, designed by Rev. Peter John Fitzpatrick (Bro. Peter). In April 1879, a great fire destroyed the main university building, but the telescope was not damaged, though its observatory was filled with rescued items. It was returned to working condition in September 1879. Plans for a new observatory led to Badin Observatory, completed in 1892, where the telescope was placed on a new mount from Warner & Swasey Co. and the original Foucault lens was refigured by J.M. Brashear. The observatory was in use until the 1930s, then dismantled, and the telescope put in storage before 1933. It remained in storage until 1955, when Father James Stilts retrieved it to observe the opposition of Mars, leaving it on the roof of Nieuwland Hall under a tarp, where it became damaged. Repairs and a protective shed were completed in 1960, featuring a roll-off roof. Since then, the telescope has been cleaned and adjusted several times, and displayed in the Hesburgh Library on two occasions: for the return of Comet Halley in 1986, and after a refurbishing in 1993.

Reader's Guide

The Napoleon III Telescope is significant as a gift from a reigning emperor to an American university, reflecting 19th-century transatlantic scientific and diplomatic ties. Its lens was designed by Léon Foucault, a leading physicist of the era, and the instrument was one of a set built exclusively for the French government. The telescope's history illustrates the challenges of maintaining a historic instrument: it survived a major fire in 1879, was stored for decades, and was damaged by weather after being left on a roof in 1955. Its legacy includes use in student observations of Jupiter, Saturn, and Mars, and its role in the university's astronomy program, which saw a Department of Astronomy founded in 1919 and later closed in 1940. The telescope remains on the roof of Nieuwland Hall, largely unnoticed, but its story has been preserved through talks at the university's Biennial History of Astronomy Workshop, including a 1995 presentation by Robert J. Havlik and Terrence Rettig. The instrument's mount and lens were upgraded in the 1890s by notable firms Warner & Swasey and J.M. Brashear, linking it to the era's major observatory projects.

Did You Know?

• The telescope was one of a set of instruments built exclusively for the French government.
• The objective lens was designed by Léon Foucault, who also invented the knife-edge test for telescope optics.
• After the Badin Observatory was dismantled, the rotating roof was reportedly used as a hot dog stand.