The University of Cagliari began its activities in the year 1626, in the reign of Philip III of Spain.Four groups of chairs were activated:Theology, Law, Medicine and Philosophy.The chair of Physics was one of the three in the philosophy group and was entrusted to the Jesuit Fathers.The University laboured on through the Spanish domination of Sardinia and the first part of the Savoy domination, which began in 1720 with the Treaty of the Hague.

It was Charles Emmanuel III, king of Sardinia who, starting from 1755, began a wide-reaching work of reorganization and expansion, which led to the official inauguration of the renewed university on 3 November 1764.

In the new university the Chair of Experimental Physics was instituted and entrusted to Father Giovanni Antonio Cossu of the Order of the Servants of Mary, a Sardinian who lectured in Philosophy in Bologna.As a first endowment of the Physics Laboratory, from Turin it received a first group of apparatuses and instruments contained in eight crates.

Of this first group, the Museum now has only four of certain provenance; many others probably belong to this first shipment, but studies are still underway to ascertain this.

In 1770, Father Cossu was succeeded by the Carmelite Father Alberto Marchi, he too a Sardinian, who held the chair up to 1784.He was followed by:Giuseppe Gagliardi (1784-1789), Antonio Conquedda (1789-1802), Vincenzo Cossu (1802-1823), Efisio Uselli (1823-1826), Stefano Sirigo (1826-1844), Antonio Cima (1844-1851).

It was during these years of the 19th century that the endowment of the Physics Laboratory was expanded and consolidated. At present the Museum possesses some two hundred and fifty apparatuses and instruments dating back to the 19th century.In particular, thanks to the presence of Gian Pietro Radicati (1853-1871) in the Chair of Experimental Physics, the number ofinstruments increased greatly following an extraordinary grant of three thousand lire in 1864.

The later presence in Cagliari of Antonio Pacinotti (1873-1881), who in Pisa had previously performed most of the scientific work that led him to the invention of his "dynamo", the first machine that generated direct current, which was to shake the world. Of his work, the Physics Museum of Cagliari possesses one of the three Dynamoelectric Machines that he built in Cagliari, the most prestigious piece of the collection. Of the other two machines, the first is now in Pisa and the other in the Science Museum of London. A functioning copy of the Pacinotti machine has recently been built by Carlo de Rubeis and Prof. Guido Pegna for the purpose of making it available to visitors to the Museum and of performing research on its characteristics, which were never published by Pacinotti.

Prior to 1939, new apparatuses and instruments were added, and some one hundred and fifty of these, perfectly restored, classified and indexed, are now in the museum. The work of finding, reconstituting, restoring and cataloguing is still ongoing concerning a large number of items stored in warehouses and often reduced to a few parts difficult to place owing to the work of savage "cannibalization" which took place in the immediate post-war period, when funds available for research were scanty or non-existent.

Besides those of Antonio Pacinotti, important traces of the presence of two other prestigious physicists remain in Cagliari: Giovanni Guglielmo (1891-1928) and Rita Brunetti (1928-1939).In particular, concerning the latter, her work environment has been reconstructed almost entirely, with spectrographs, original furniture and furnishings which have been conserved up to the present. This work environment can be visited at the Physics Museum of Cagliari.

Starting from 1955, the Chair of Experimental Physics was occupied by Prof. Giuseppe Frongia, up to the time of his death.In all probability it is owing to his far-sighted work that all the apparatuses and instruments of historical interest present in Cagliari have been conserved: first of all because of the attention and care that he devoted to them, keeping them in order in the large cabinets of the old Institute of Physics in the Via Ospedale; furthermore (but this is still to be verified), during the Second World War when the Institute of Physics was occupied by the homeless and the town was in the hands of the German occupying forces, he had them packed and taken, apparently to Sanluri, in a convoy of lorries of the Italian Army.

The author of this article is honoured to have begun his academic career as Prof. Frongia's assistant, and is grateful for the opportunity to mention him herein.

Guido Pegna