(b. Fermo, Italy, 1540; d. Florence [?], Italy, 15 January 1603)
mathematics, military engineering.
Ricci was the son of Orazio Ricci and Elisabetta Gualteroni, patricians of Fermo. It is not known with any certainty where he studied mathematics, but some of his intellectual influences perhaps may be conjectured: Leonardo Olschki has likened his teaching to that of Niccolò Tartaglia, and Thomas Settle has pointed out a remarkable connection of Ricci with Leon Battista Alberti (see below). Ricci began, probably in 1580, to teach mathematics and likely military engineering to the pages of Francesco de’ Medici, grand duke of Tuscany. In 1583, he also gave instruction to Galileo, the son of his friend Vincenzo Galilei, who was then nineteen years old and a medical student at the University of Pisa. Under Ricci’s tutelage, Galileo studied Euclid and, later, Archimedes (a set of whose works Ricci gave to Galileo). Galileo also attended, with Ludovico Cardi da Cigoli and Giovanni de’ Medici, the lessons on perspective that Ricci gave at the house of Bernardo Buontalenti in Florence, presumably around 1585. When Galileo applied for a chair at the University of Bologna in 1587, Ricci recommended him; he was also helpful in attaining for Galileo the chair of mathematics at the University of Pisa two years later.
Ricci was also active as an engineer. Around 1590 he was in Ferrara to study the courses of streams in that region and in the area of Bologna, a subject on which he wrote a report. He returned to Florence (from 1593 he taught at the Academy of Design) and in 1597, during a conflict between Tuscany and France, he directed the construction of fortifications on the islands off Marseilles. Later, according to his biographer Carlo Promis, he worked as a military engineer in Ferrara during the controversy between Pope Clement VIII and Cesare d’Este in 1597–1598.
Although he wrote on both mathematics and engineering, Ricci did not publish his works. Of the manuscripts that remain, two are of particular importance in establishing Ricci’s influence on Galileo. One of these, a mathematical manuscript attributed to Ricci and probably used by him in his teaching, has been identified by Thomas Settle as a copy of Alberti’s Ludi matematici. Settle emphasizes Ricci’s role as the spiritual intermediary between Alberti and Galileo; Alberti’s influence, transmitted by Ricci, is apparent in Galileo’s thought and experimental methods, and in some of his specific works, particularly La bilancetta. The other, a tract entitled “Libro primo delle forti- ficationi di M. Hostilio Ricci da Fermo,” was discovered in Pesaro by Promis, who, in his biography of Ricci, noted the similarity between it and the treatise on fortifications by Galileo, and suggested that Galileo had probably been instructed in this subject by Ricci.
Of the few other manuscripts by Ricci, there may be mentioned a brief treatise taken from one of the Florentine manuscripts; it was published in 1929 by Federico Vinci under the title “L’uso dell’archimetro ovvero del modo di misurare con la vista.” The manuscript is dated 1590, and deals with the use of the “archimeter,” a simple instrument for the visual measurement of inaccessible distances, heights, and depths through the properties of similar triangles. Another manuscript, of which there is mention under the title “Intorno ad una leva ad argano,” is now apparently lost. A manuscript of Giorgio Vasari (Rome, Biblioteca Angelica, n. 2220) mentions Ricci as solver of a peculiar geometrical question.
I. Original Works. “L’uso dell’archimetro” exists in two MSS at the National Library in Florence: Codici Magliabechiani II, 57, and VII, 380; the former was published in Federico Vinci, Ostilio Ricci da Fermo, maestro di Galileo Galilei (Fermo, 139), 23–29, with nine facsimile figures. This is presumably the same work mentioned by Targioni-Tozzetti (p. 298) and Promis (p. 349) under the title L’uso dell’aritmetica; it is likely also the work described as concerning “il modo di misurare colla vista” by Nelli (p. 35), Fracassetti (pp. 30, 103), and Promis (p.349), for which see below.
MS Gal. 10 (div. 1, anteriori, vol. X) in the Galilean Collection of the National Library, Florence, is entitled “Ricci Ostilio. Problemi geometrici.” It is described in Angiolo Procissi, La collezione Galileiana nella Biblioteca nazionale di Firenze, I (Rome, 1959), 10. Fols. la-16a are derived from Alberti (Settle, pp. 121, 124). Settle also cites (p. 125, notes 6, 8, 9) various biographical documents on Ricci in the state archives of Florence, one of which gives the date of Ricci’s death.
For Ricci’s works on military fortifications, see Promis (pp. 341, 347–348) and the catalogs of the Campori collection, which is now at the Estense Library, Modena: Luigi Lodi, Catalogo dei codici e degli autografi posseduti dal marchese Giuseppe Campori (Modena, 1875), 273, art. 622; and Raimondo Vandini, Appendice prima al catalogo dei codici e manoscritti posseduti dal marchese Giuseppe Campori (Modena, 1886), 250, art. 753.
On Ricci’s report on the waters of the Ferrara-Bologna region, see Frizzi, V, 28; and Promis, p. 343.
II. Secondary Literature. Publications concerning Ricci’s relations with Galileo are of particular interest. Mentions of Ricci in Galileo’s application of 1587 and in the biographies of Galileo by Vincenzo Viviani and Niccolò Gherardini are in Le opere di Galileo Galilei, Antonio Favaro, ed., XIX (Florence, 1907), 36, 604–605, 636–638; Gherardini mistakenly called Ricci a priest, and Libri later called him an abbé. Ricci as a teacher is mentioned in a biography of Cigoli written in 1628 by his nephew Giovan Battista Cardi and published by Guido Battelli, Vita di Lodovico Cardi Cigoli (Florence, 1913), 14.
An early biography of Ricci is Giuseppe Santini, Picenorum mathematicorum elogia (Macerata, 1779), 51–52. In 1830 Giuseppe Fracassetti delivered to the Accademia Tiberina of Rome his Elogio di messer Ostilio Ricci da Fermo (Fermo, 1830); Fracassetti later contributed a biography of Ricci to Antonio Hercolani, ed., Biografie e ritratti di uomini illustri Piceni, I (Forli, 1837), 97–106. See also Carlo Promis’ biography of Ricci in “Gli ingegneri militari della Marca d’Ancona…,” in Miscellanea di storia italiana, 6 (1865), 339–349. Vinci (see above) includes a biography of Ricci (pp. 7–21), his coat of arms, and notes on his family; there are also citations of biographical works on Ricci by Mistichelli (1844) and Giannini (1874), and of unpublished MSS by Eufemio Vinci on the nobility and leading men of Fermo, in the historical archives of the Vinci family in Fermo.
See also Giovan Battista Clemente de’ Nelli, Vita e commercio letterario di Galilei (Florence, 1793), 35–36, 46, 797; Antonio Favaro, Galioleo Galilei e lo Studio di Padova (Florence, 1883), I, 16–19, 23, 31—new ed. (Padua, 1966), I, 13–15, 18, 24; Antonio Frizzi, Memorie per la storia di Ferrara, V (Ferrara, 1809), 28; Riguccio Galluzzi, Istoria del Granducato di Toscana sotto il governo della Casa Medici (Florence, 1781), III, 291; also in Capolago, 1841 ed., V, 67; Guillaume Libri, Histoire des sciences mathématiques en Italie, IV (Paris, 1841; 2nd ed., Halle, 1865; repr. Bologna, 1967), 173–174; Ernan McMullin, ed., Galileo, Man of Science (New York, 1967), 53, 122, 234–235; Leonardo Olschki, Geschichte der neusprachlichen wissenschaftlichen Literatur, III, Galilei und seine Zeit (Halle, 1927; repr. Vaduz, 1865), 141–153; Thomas B. Settle, “Ostilio Ricci, A Bridge Between Alberti and Galileo,” in Acts of the Twelfth International Congress on the History of Sciences, IIIB(Paris, 1971), 121–126; and Giovanni Targioni-Tozzetti, Notizie sulla storia delle scienze fisiche in Toscana (Florence, 1832), 298, 300.