Potsdam Great Refractor

Potsdam Great Refractor is an historic astronomical telescope in an observatory in Potsdam, Germany.Completed in 1899, it is a double telescope for astronomy, a great refractor with two objectives of different size on the same equatorial mount. One lens in 80 cm in aperture and the other is 50 cm. The 80 cm diameter lens was designed for astrophotography, and the 50 cm diameter lens for visual work.The telescope was made by Repsold,. The objective lens glass blanks were made in Jena by Schott, and the lenses figured by Steinheil of Munich.

Source: Wikipedia