Fraunhofer Glashütte

The Fraunhofer Museum in Benediktbeuern is located in the historic glassworks where the optician Joseph von Fraunhofer worked between 1807 and 1819. In the workshop preserved in its original state, a small exhibition commemorates this decisive phase in the production of optical glass.

The site is situated in the former Benediktbeuern monastery, whose buildings were acquired in 1805 and converted into two separate glassworks. One of these served the production of optical glass and was known as the Optical Institute; its management was initially taken over by a specialist in glassmaking. Fraunhofer joined this enterprise in 1807, assumed responsibility for glass grinding in 1809, and became head of the entire institute in 1811. After 1814, Fraunhofer and his business partner became the sole proprietors.

In Benediktbeuern, Fraunhofer developed new grinding machines and improved glass formulations, in particular striae-free crown and flint glass, which significantly enhanced the optical quality of lenses. His technical solution for achromatic lens systems—placing two lenses one behind the other with an air gap instead of cementing—expanded the options for correcting imaging aberrations and proved to be of lasting importance in astronomy; the so-called Fraunhofer achromats are still used in amateur astronomy today. Prominent scientists and public figures visited the institute, underscoring its scientific significance.

In 1819 the Optical Institute moved to Munich; the manufacture of utility glass in Benediktbeuern declined and later ceased, and the associated glassworks building was demolished in 1843. Production of optical glass continued until 1887. In 1963 the Fraunhofer-Gesellschaft established an exhibition in the glassworks; the museum was last modernized in 2008 and is maintained by the Fraunhofer-Gesellschaft. The exhibition displays, among other items, two large melting furnaces with stirring gear, explanatory display panels, optical instruments, and tools for glass and metalworking.

The building is listed (entry: Ehem. Fraunhofer-Glashütte, jetzt Fraunhofer-Museum; D-1-73-113-24). It is a two-storey, partially clad timber structure with a gabled roof; the core dates from the late 17th century, with alterations carried out in 1843.