243
© Springer Nature Switzerland AG 2021
I. Chinnici, G. Consolmagno (eds.), Angelo Secchi and Nineteenth Century Science,
Historical & Cultural Astronomy, https://doi.org/10.1007/978-3-030-58384-2_15
Chapter 15
Angelo Secchi and the Measurement
of Time
Maria Luisa Tuscano
15.1 Introduction
The sundials and meridian lines devised by Fr. Angelo Secchi, still existing in Italy
in some locations where he went for his many cultural activities, prove his interest
in the measurement of time. Though it was perhaps only a small part of his limitless
thirst for knowledge, nonetheless it has interesting connections with his professional and public work.
“An exact measure of Time is the foundation of all astronomy: it is inferred from
the rotation of the celestial sphere, which is uniform.” With this sentence, Secchi
opened his Principi di Astronomia (Principles of Astronomy), compiled in 1862 for
the schools of the Roman College. It confirms the primary role that he attributed to
this subject for the proper formation of the students. From some of the items in
Secchi’s papers (Chinnici and Gramatowski 2001) which are held in the archives of
the Pontifical Gregorian University, one can see that he saw this work as a part of
his service to the territory of the Holy See.
1
1 The identification of these papers was made possible thanks to information found in: Chinnici,
Ileana - Gramatowski, Wiktor, 2001. “Le carte di Angelo Secchi conservate presso l’archivio della
P. Università Gregoriana. Un inventario inedito rivisitato”, Nuncius, XVI, 2, pp. 571–627.
M. L. Tuscano (*)
Società Italiana degli Storici della Fisica e dell’Astronomia, Società Italiana di
Archeoastronomia, Palermo, Italy
© Springer Nature Switzerland AG 2021
I. Chinnici, G. Consolmagno (eds.), Angelo Secchi and Nineteenth Century Science,
Historical & Cultural Astronomy, https://doi.org/10.1007/978-3-030-58384-2_15
Chapter 15
Angelo Secchi and the Measurement
of Time
Maria Luisa Tuscano
15.1 Introduction
The sundials and meridian lines devised by Fr. Angelo Secchi, still existing in Italy
in some locations where he went for his many cultural activities, prove his interest
in the measurement of time. Though it was perhaps only a small part of his limitless
thirst for knowledge, nonetheless it has interesting connections with his professional and public work.
“An exact measure of Time is the foundation of all astronomy: it is inferred from
the rotation of the celestial sphere, which is uniform.” With this sentence, Secchi
opened his Principi di Astronomia (Principles of Astronomy), compiled in 1862 for
the schools of the Roman College. It confirms the primary role that he attributed to
this subject for the proper formation of the students. From some of the items in
Secchi’s papers (Chinnici and Gramatowski 2001) which are held in the archives of
the Pontifical Gregorian University, one can see that he saw this work as a part of
his service to the territory of the Holy See.
1
1 The identification of these papers was made possible thanks to information found in: Chinnici,
Ileana - Gramatowski, Wiktor, 2001. “Le carte di Angelo Secchi conservate presso l’archivio della
P. Università Gregoriana. Un inventario inedito rivisitato”, Nuncius, XVI, 2, pp. 571–627.
M. L. Tuscano (*)
Società Italiana degli Storici della Fisica e dell’Astronomia, Società Italiana di
Archeoastronomia, Palermo, Italy