“Esposizione del 1867”

"Viaggio in Inghilterra e ritorno per la Svizzera”
[Angelo Secchi]
Manuscript diary,
Fondo Secchi 23.2.A
Archive of Pontificia Università Gregoriana, Rome

The Secchi Fund of APUG also preserves some of the travel logs of Secchi, full with annotations that show very well the curiosity of the scientist, his humor, his approach to problematic situations. From the diaries we also know about the numerous official invitations received from various academies and the personal invitations of some colleagues, the numerous visits to scientists, institutions, museums, attractions, workshops, laboratories, etc.
In the pages reproduced here, related to the diary of the Voyage in Paris of 1867, Secchi notes a visit to the physicist Léon Foucault and draws a sketch of a part of the apparatus for the measurement of the speed of the light, which he showed to him. It is worth mentioning that in 1851 Secchi had repeated the famous experiment of the Foucault pendulum in the Church of St. Ignatius in Rome, to prove the rotation of the Earth.
In the same pages reproduced here there is a trace of an invitation to the house of Urbain Leverrier, director of the Observatoire de Paris, and of the conversations held in that house with other scientists. Secchi notes ironically that the lunch with Leverrier still had a price, because the Jesuit was forced to take an expensive car to return due to bad weather conditions.
In the same diary, on July 1 (Figure 1), Secchi begins with the words: “Today’s great Day” alluding to the assignment of the Grand Prix for the meteorographer and the bestowal of the Legion of honor, declaring that it was a “true Triumph for Science. ”
In the preliminary papers of a small diary of autumn 1872 (Figure 2) instead, relating to the trip to Paris for the International Conference of the Metro, a number of expenses are listed including, in addition to those foreseeable for transport and tickets in the trip from Turin to Lyon, the ones relative to the purchase of some personal items (umbrella, gloves, and Knitting socks) necessary for the trip.

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