INTRODUCTION

The collection of the early instruments of the Departiment of Physics of the University of Naples includes about 400 pieces. They may be ascribed to the years beginning from 1820, with the exception of the very antique lens made in Florence by Evangelista Torricelli around 1645 and of the portable sundial made in Naples in 1769. At least 250 instruments were manufactured in the last century. The earliest historical informations about the scientific patrimony of the Institute of Physics of the University of Naples date back to the time of the School of Physics of the Royal University. The oldest instruments of the collection, certainly Torricelli's lens, portable sundial, dilatation pyrometer and two mariner's compasses, belonged to the School as from the begenning of the 19th century. Until 1840 the scientific equipments of the school were of little importance since the physics researches performed at that time in Naples were rather marginal and out of the debate in which the leading scientists of that period were involved. With the arrival of Macedonio Melloni (1798, 1854) the scientific studies had a remarkable growth. He came to Naples in 1839 having been appointed, by Ferdinando II di Borbone, Honorary Professor of Physics and Director of the Osservatorio Vesuviano (Vesuvius observatory) not yet erected. The Osservatorio Vesuviano was opened only in 1845 but it was practically inactive until 1850, when Luigi Palmieri (1807,1896) was appointed Director. Owing to his implication in the liberal rising in Naples, Melloni in 1848 was removed from all the pubblic offices. Melloni, during his long stay in Naples, continued and enlarged his studies on the properties of the radiant energy, thus obtaining very important results. Some astatic galvanometers, the condenser electroscope, the large echelon lens built in Paris by Henry Lepaute and the benchs used by Melloni for measurements of radiant heat, belong to this period. After Melloni's death (1854), these apparatus were given by the widow to the School together with other instruments bought in Paris and in London for the Osservatorio and not utilized for this purpose. Successively, after the fall of the Borbonic Monarchy (1860), all the equipments of the School were assigned to the Gabinetto di Fisica (Laboratory of Physics), founded in 1861. Many of the instruments destined for the Osservatorio got lost. Among the surviving ones, there is an ingenious electroscope devised by Melloni. The characteristics of the instrument, very different from those of the traditional leaf electroscope, were reported by the author in a manuscript which he intended to present at a meeting of the Neapolitan Academy of Sciences. However, his sudden death, a few days prior to the event, prevented him from doing it and the description of the instrument was read by Antonio Nobile (1794,1863), eminent astronomer of the Osservatorio di Capodimonte in Naples. With the assignment of Gilberto Govi (1826,1888) to Professor of Physics at the University of Naples, in 1878, many instruments, mainly optical, enriched the Laboratory of Physics. Other instruments, mostly galvanometers, were acquired after the appointment of Emilio Villari (1836,1904) to Director of the Laboratory. The comparison with apparatus of similar features allows to assign an approximate dating to the instruments of which the manufacture year is unknown. The microscope section turns out particularly interesting since through the informations gathered on the microscopes being part of the collection it is possible to remake, even in short, the history of the optical microscopy from 1830 to the end of the last century. Also the current meters are notable for variety, historical interest and state of preservation.

The Museum of the Department of Physics started in 1983. Since then, over 400 instruments have been collected, studied and catalogued. The inventory is complete at the level of 80%. Many exhibitions have been organized and the publications are listed in the following. The Museum is not currently open to visitors (but it is foreseen in next future), except in occasions of exhibitions and organized visits.

E.Ragozzino and E.Schettino

Publications:

enter exhibit