Among the most representative instruments of the meteorological station at the Capodimonte Astronomical Observatory, still preserved in its historical collections, is the Richard recording barometer, a refined French device from the late nineteenth century. Equipped with eight aneroid capsules, the instrument amplifies atmospheric pressure variations and records them on a paper strip wrapped around a rotating drum. Capable of producing a continuous and legible trace of barometric oscillations, it stands as one of the earliest examples of automatic recording in meteorology.
Designed by Jules Richard and patented in 1880 together with his brother Félix, the barograph featured an innovative system that inscribed data onto smoked paper. The Richard firm, founded in 1845 in Paris by their father Félix and specialized in Bourdon-type metallic barometers with compensated tubes, was among the first in Europe to manufacture meteorological instruments with automatic recording, playing a key role in the modernization of atmospheric observation.
The barograph was supplied to the Naples Observatory by the Central Meteorological Office, which distributed standardized instruments to Italian stations for consistent data collection.
Starting in 1877, the meteorological station was housed in an isolated room in the northern wing of the Villa della Riccia, specifically designated for atmospheric observations. In this controlled environment, shielded and ventilated, fundamental data were collected for decades, contributing to national climatology and meteorology.
In addition to the barograph, the station was equipped with various mercury barometers, including the Deleuil cistern barometer, the Casella barometer (fitted with a mercury thermometer showing both Celsius and Fahrenheit scales at the base of its brass tube), and the Bunten siphon barometer. The collection also included mercury and alcohol thermometers, such as Casella’s, and the Richard thermograph, used to record maximum, minimum, and temperature variations.
Other instruments, no longer preserved, included an August psychrometer with Cantoni ventilator for measuring relative humidity; a sevenfold rain gauge with lead basin and graduated tube; an atmometer for evaporation measurement; and a Brassart anemograph for recording wind direction and intensity.
In 1900, on the proposal of astronomer Francesco Contarino, the so-called “meteorological window”, which housed the rain gauge, thermograph, and atmometer, was transformed into a meteorological balcony. The instruments were suspended outside the new opening, shielded from solar radiation by a Stephenson-type screen. To protect them from internal heat sources, glass shutters were installed, which, like the wooden blinds, remained permanently closed.

___Mauro Gargano