Merz, Munich, ca. 1850

Brass, glass;
Aperture ø 11,5 cm
Focal length f= 190 cm

INAF – Rome Astronomical Observatory

This refracting telescope, built in the Merz workshop, was donated to the Campidoglio Observatory, directed by Ignazio Calandrelli (1792-1866), by the marquis Giuseppe Ferrajoli (1798-1870), a well-known financier, businessman and politician living in Rome during Pio IX’s papacy. The telescope was first used by the astronomer Caterina Scarpellini (1808-1873) during the solar eclipse of 18 July 1860. However, it was Lorenzo Respighi who made an intense use of this instrument for his studies of stellar and solar astrophysics, starting from 1865, when Pio IX nominated him director of the Observatory. By adapting the objective prism he had previously invented to this telescope, he succeeded in demonstrating that the star scintillation phenomenon was due to turbulence of the Earth’s atmosphere. With this telescope Respighi also did research work on the solar chromosphere: by placing the spectroscope slit tangentially to the photosphere limb, he could obtain the prominences profiles and follow their chronologic evolution on various timescales. When the new Rome Astronomical Observatory (OAR) was established, the telescope was transferred to its new location at Villa Mellini, on Monte Mario where it was used until the ’70s of the 20th century. On the occasion of the total solar eclipse of 15 February 1961 it was moved to Imperia and placed at the astronomical camp arranged by Rome Observatory staff. After its dismissal, the telescope was included in the collection of historical instruments on exhibition at Monte Porzio Catone Observatory, i.e. the current venue of the Rome Observatory, whereas the marble stand on which the equatorial mounting rested, is still visible at Monte Mario, in the garden of Villa Mellini, which currently hosts the Presidency of INAF. [a.a., m.f., f.p.]

Bibl.: Scarpellini 1860; MONACO 2000.