Catholic Encyclopedia (1913)/Balthasar Boncompagni
Italian mathematician, b. at Rome, 10 May, 1821; d. 13 April, 1894. He was a member of the illustrious family to which had belonged Gregory XIII, the reformer of the calendar. He studied mathematics and physics under Santucci and became known as a prolific writer on mathematical and historical subjects. At an early age (1840) he contributed to the "Giornale Arcadico" biographical sketches of Father Joseph Calandrelli, director of the observatory of the Roman College after the suppression of the Society of Jesus, and his assistant Conti. These were followed by his "Recherches sur les intégrales définies", which appeared in "Crelle's Journal" (Berlin). In 1846 the "Giornale Arcadico" published his "Studi intorno ad alcuni avanzamenti della fisica in Italia nei secoli XVI e XVIII". In 1847 he became a member of the Accademia dei Lincei and shortly after its librarian.
Boncompagni contributed much to the study of the history of mathematics by his "Bolletino", which he founded in 1868 and conducted until 1887. To it he contributed numerous essays, biographies, reviews, etc. Among his essays published before the founding of the "Bolletino" may be mentioned, "Della vita e delle opere di Gherardo Cremonese traduttore del secolo XII" (1850); "Gherardo da Sabionetta, astronomo del secolo XIII" (1851); "Della vita e delle opere di Guido Bonatti" (1851); "Memoria sopra Leonardo" (1854); "Saggio intorno ad alcune opere di Leonardo" (1854); "Tre scritti inediti di Leonardo da un manoscritto dell' Ambrosiana di Milano" (Florence, 1854); "Intorno ad una proprietà dei numeri" (in the "Annali delle scienze matematiche e fisiche" 1855); "Scritti inediti del P. D. Pietro Cossali" (1857); "Dissertazione intorno ad un trattato di aritmetica stampato nel 1478" (in the "Atti dei Nuovi Lincei" 1862-63). In 1857 Boncompagni also published the "Algoritmi de numero Indorum" which he had found in the Library of Cambridge University. It is supposed to be a translation of the famous treatise on arithmetic of Al-khwarizmi, the most illustrious of the Arabian mathematicians.
Nuova Enciclopedia Italiana, Suppl., 6th ed., Turin; BALL, Hist. of Mathematics (New York, 1888).
H. M. BROCK