“Ancona Lighthouse” and “Civitavecchia Lighthouse”

“Cenni storici dei fari antichi più famosi e di alcuni moderni”
Alessandro Cialdi
Triplice omaggio alla Santità di Papa Pio IX nel suo giubileo Episcopale offerto dalle tre romane accademie, Tipografia della Pace, Roma, 1877
Tav. I
230 x 330 mm
Library of Specola Vaticana, Albano Laziale (Rome)

In addition to his research, teaching and dissemination activities, Secchi had an intense activity of technical-scientific consultant for the Papal States. He dealt with numerous aspects related to civil protection, from the placement of lightning rods in the monuments to fire-fighting measures in the Roman basilicas, from the weather alert services to the introduction of electric railways in the Papal States. In particular, its involvement in the renewal of the lighthouses of the main ports of the Papal States should be recalled. Since the end of the XVIII century enormous advances in the construction of the lighthouses were made, the importance of which was fundamental for a safe navigation. Light sources underwent through several improvement processes (for instance, the Argand lamp was introduced, brighter and less smoky than those used previously, and the construction of silver plated parabolic reflectors) . But a fundamental progress was made in the early 20s of the XIX century by the French physicist Augustin Fresnel. He devised a revolutionary system of prismatic lenses and rings that allowed to send a parallel beam of light in a way much more effective than the reflectors used until then.
In 1858 a special commission with the task of renew the headlights of the ports of the Papal States and to build new ones was established. Secchi was appointed member of this Commission and he was commissioned to visit some large foreign ports to see which modern lighting system could be used in papal headlights. Before leaving, Secchi had the opportunity to visit the lighthouse of Civitavecchia, which he found in a pitiful state. Not only was the building unsafe and unstable but the whole lighting system was rusty, dirty and malfunctioning. Once embarked, Secchi visited the ports of Genoa and Marseille and then proceeded by train to Paris. In the French capital he met several instrument builders and also visited the famous workshop of Augustin Henri-LePaute, specialized in lamp construction and lighthouse mechanisms. Secchi continued to London, where he met William Crane Wilkins, an engineer whose lighthouse-building company was among the most reputed. Finally, in the company of physicist Michel Faraday, who was a member of the Royal Commission for Lighthouses, he inspected a lighthouse under construction at Trinity House.
Following the mission of Secchi, the lighthouses of Ancona and Civitavecchia (rekindled in 1860), as well as the three new lighthouses, inaugurated in 1866, were equipped with Fresnel lamps supplied by LePaute. For example, the lantern of Civitavecchia had a lenticular system of second order with white light rotating (with flashes with eclipse) of the internal diameter of 1.5 meters.

Paolo Brenni, CNR e Fondazione Scienza e Tecnica