Meteorological observations in the Real Gabinetto Fisico

Few institutions carried out meterological observations in the Neapolitan area since the first half of the 19th century: the Royal Astronomical Observatory in Capodimonte established in 1819, the Vesuvian Observatory inaugurated in 1845 during the 7th Meeting of the Italian Scientists in Naples, and the Physics Cabinet located at the Royal Palace. The little know, though interesting, scientific activity pursued at the Real Gabinetto Fisico, focused mainly on geodetic operations and meteorological observation, emerges from documents at the State Archives in Naples.
Many tables, technical reports, drawings and notebooks record the broad observational activity in the field of meterology, regularly pursued in Naples at the Royal Physics Cabinet from 1842 until 1857. Data collection generally took place every day, once or twice a day, using two barometers and a standard thermometer built by Newman in London, as well as an English thermometer by Cetti, placed in the shade outside the Royal Palace, close to the facade running from North-North-West to South-South-East. The barometer’s height was expressed in English inches, while the temperatures were given in degrees Fahrenheit and Reamur. The data were supplemented by conversion tables from English inches to French and Neapolitan units (fig. 1), and from degrees Reamur and Fahrenheit to each other and to Celsius, respectively. Summary tables were provided, showing the monthly average temperature, as well as the maximun and minimun temperatures recorded during the year.
Observations carried out concerned a variety of climate and environmental issues: pressure, temperature, humidity, wind direction and strength, rain, the status of the sky and tides in the Gulf of Naples. Interstingly, also data from an aneroid barometer were collected, while thermo-hygrometric measurements were performed by comparing the readings from two thermometers, one of which was wet (fig. 2).
In-depth notes concerning atmospheric electricity during thunderstorms, earthquakes, and the state of Mount Vesuvius were often recorded, aimed at investigating the possible interaction between atmospheric, seismic and volcanic phenomena.
Finally, a report has been found in the archival documents, concerning catastrophic atmospheric events occurred during the year 1857, such as heavy rains, floods, hurricanes and related phenomenology (including severe damage to houses, trees and people) observed in various places of the Kingdom of the Two Sicilies, ranging from the Neapolitan area to Calabria, Apulia and Sicily.

___Salvatore Esposito & Adele Naddeo