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Castelli, Benedetto

1. Dates
Born: Brescia, 1577 (or possibly 1578)
Died: Rome, 9 April 1643
Dateinfo: Birth Uncertain
Lifespan: 66
2. Father
Occupation: Aristocrat
Annibale Castelli was from an aristocratic family.
No information on financial status.
3. Nationality
Birth: Italy
Career: Italy
Death: Italy
4. Education
Schooling: Padua
Studied under Galileo in Padua. There is no mention of a B.A.
5. Religion
Affiliation: Catholic, a Benedictine
6. Scientific Disciplines
Primary: Astronomy, Hydraulics, Physics
Subordinate: Optics, Mathematics
7. Means of Support
Primary: Church Life, Academia, Patronage
Secondary: Schoolmastering
1595, entered Benedictine order, took name of `Benedetto'.
Before 1604, moved to the monastery of Santa Giustina, Padua.
1607, monastery of Cava dei Tirreni.
By 1610, had returned to native city of Brescia.
1611, moved to Florence, where he stayed in the Badia, which I think was a Jesuit monastery. He gave private lessons in Florence.
1613, Professor of Mathematics at Pisa. Confirmed for life, 1624. Resigned, 1626.
1626, Professor of Mathematics at Rome. He also instructed Taddeo Barberini.
He continued to hold ecclesiastical positions. In 1632 he became Abbot of a monastery; ultimately he was abbot of four monasteries, none of which he actually governed.
8. Patronage
Types: Scientist, Court, Ecclesiastical Official
1610, upon receiving copy of Siderius Nuncius from Galileo, his former teacher, he requested and was granted transfer to Florence. Galileo was responsible for his appointment at Pisa.
1613, reported to Galileo on an attack on him at the table of the Grand Duke of Tuscany.
1613, at Galileo's instigation he was offered a chair at the university, (see 6 above). While in Pisa he tutored the Medici prince Lorenzo.
1615, Galileo entrusted to Castelli his response to his critics in the polemic on floating bodies.
Castelli went to Rome to see how the land lay under the new Pope in 1624 (or 25). It was on that occasion that the Pope sent him to investigate the Po valley with Corsini.
About 1626, was called by Urban VIII to Rome to assume chair at the university (see 6 g.), to be a consultant on hydraulics, and to tutor Taddeo Barberini. Castelli received a pension of 150 scudi.
The Pope ordered the publication of Castelli's book, which was dedicated to Urban and was published by the Papal press.
Nevertheless there is good evidence that Castelli found his position in Rome galling and struggled unsuccessfully to leave. See the final pages of Favaro.
9. Technological Involvement
Types: Hydraulics, Instruments
He suggested to Galileo the method of observing sunspots, really a device.
He apparently first suggested a device to measure rainfall.
1626, papal consultant on hydraulics. (Presumably having to do with river management.) Indeed Castelli's entire career was devoted primarily to this practical activity.
10. Scientific Societies
Memberships: None
Connections: Knew Galileo very well. Taught Borelli, Cavalieri, and Toricelli.
  1. A. De Ferrari, "Castelli, Benedetto," in Dizionario biografico degli Italiani, 21 (Rome, 1978), 686-690.
  2. A. Favaro, "Amici e corrispondenti di Galileo Galilei, XXI - Benedetto Castelli," in Atti del Reale Istituto veneto di scienze, lettre, ed arti, 67 pt. 2 (1907-8), 1-130.
  3. G. Abetti, Amici e nemici di Galileo, Milano, 1945.
  4. Incidentally I found this awful; don't bother with this work further.
  5. G. Arrighi, "Benedetto Castelli: considerazioni e proposte," in G. Arrighi et al., La scuola galileiana, (Firenze, 1979), pp. 3-11.
  6. _____, "Benedetto Castelli: il primo discepolo," in Carlo Maccagni, ed., Saggi su Galileo Galilei, (Firenze, 1972), pp. 625-36.
  7. Benedetto Castelli, Carteggio, ed. Massimo Bucciantini (Archivio della corrispondenza degli scienziati italiana), (Firenze: Olschki, 1988). There is no biographical sketch in this volume.
Not Available and Not Consulted
  1. G.L. Masetti Zannini, La vita di Benedetto Castelli (Brescia, 1961). Massimo Bucciantini, "Atomi geometria e teologia nella filosofia galileiana di Benedetto Castelli," in M. Bucciantini and M.
  2. Torrini, eds. Geometria e atomismo nella scuola galileiana, (Firenze, 1992), pp. 171-91.
Compiled by:
Richard S. Westfall
Department of History and Philosophy of Science
Indiana University

Note: the creators of the Galileo Project and this catalogue cannot answer email on geneological questions.

1995 Al Van Helden
Last updated
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