“Sull’epoca vera e la durata della cecità del Galileo”

[Angelo Secchi]
Manuscript, 1868 ca.
Fondo Secchi 26.8
Archives of Pontificia Università Gregoriana, Rome

In the Secchi fund of APUG, there are also numerous manuscripts of interventions at conferences, reports or lectures held in various occasions; there are also papers concerning the administration of the Roman College Observatory, notebooks where the measurements of observations or astronomical calculations were recorded, press cuttings and printed publications of Secchi or received by him for various reasons, even from characters who entered into controversy with him.
Indeed, there were quite a lot of controversies, of scientific, theological or personal nature, in which Secchi was involved, due to his strong personality.
The manuscript of which the frontispiece is depicted here is about a conference, the text was published in the Arcadico newspaper, new series, 54 (1868) and relates to the dispute with physicist Paolo Volpicelli, arisen following the discovery in France of some letters, then turned out to be false, attributing the paternity of the law of gravitation Universal to Blaise Pascal, instead of Isaac Newton. In the letters some observations of Galileo Galilei were cited, occurred in a time when the famous astronomer from Pisa would already be deprived of sight.
The manuscript proves the interest that Secchi had also for the historical studies, which always faced with scientific approach and which, together with the archaeological and paleontological studies, constituted one of its preferred diversives.

Irene Pedretti, Pontificia Università Gregoriana
Ileana Chinnici, INAF-Palermo Astronomical Observatory