Merz Telescope

This telescope was the first telescope of the newly founded Specola Vaticana in 1891. It has an aperture of 10.2 cm and a focal length of 1.5 m, and was manufactured by G. Merz & Sons of Munich around 1865. It originally belonged to the Marquis Raimondo Montecuccoli Laderchi (1802-1873), who had operated a private observatory at Modena.

When Francesco Denza became the director of the Specola in 1891, he was able to obtain a set of instruments from the estate of Marquis of Montecuccoli including the transit telescope and two Merz refractors, this one on an equatorial mounting and a second one of 10.6 cm aperture on an altazimuth mounting (currently located at the Specola headquarters). It was installed atop the Tower of the Winds in a dome 3.5 meters wide with a slit opening of 58 cm, the first of four telescope domes to be erected at the Vatican. In 1907 this telescope and its dome were moved to the “half-tower” – named for its semicircular form – on the wall of the Vatican between the two large towers and near the Lourdes grotto.

This telescope was used by Fr. Joahnn Hagen SJ, the director of the Vatican Observatory from 1906 to 1930, to re-examine the colors of all the stars listed by Fr. Benedetto Sestini SJ at the Roman College Observatory during the years 1844-1846.