The Palermo Merz Equatorial Telescope. An Instrument, a Manuscript, Some Drawings.

A manuscript by Georg and Sigmund Merz dated 1862 and containing instructions for assembling the equatorial telescope acquired by the Palermo Observatory is conserved in the archives of the Museo Astronomico e Copernicano in Rome. It is a rare document that reveals "tricks of the trade" and technical knowledge not usually included in textbooks or treatises. It was sent to the Palermo Observatory as an aid to the installation of the telescope, which made a signal contribution to the development of solar physics in Italy in the 19th century. Based on the study of unpublished sources (consisting of texts and drawings), the history of the instrument has been retraced. This paper presents a detailed description of the Merz manuscript (including a complete transcript) and some technical drawings recently discovered in the archives of the Palermo Observatory.