Campani, Giuseppe

(b. Castel San Felice, near Spoleto, Italy, 1635; d. Rome, Italy, 28 July 1715),

astronomy, microscopy, horology.

Campani was a member of a peasant family and left his native village as a youth to obtain an education in Rome. While learning the new profession of lens grinding, he worked with his two brothers, Matteo Campani degli Alimeni, pastor of the church of San Tommaso in Via Parione, and Pier Tommaso, a clockmaker in the Vatican palaces, in the invention of a silent night clock. Presented to Pope Alexander VII in 1656, the clock brought Giuseppe into prominence; and he went on to produce lenses and telescopes whose superior workmanship earned him recognition from such patrons as Archduke Ferdinand II of Tuscany, Cardinal Francesco Barberini, and Giovanni Domenico Cassini at the Royal Observatory at Paris.

In 1663–1664 Campani invented the composite lens eyepiece and constructed a telescope with four lenses, consisting of a triple ocular and an objective. In 1664 he developed a lens-grinding machine lathe that could grind and polish lenses without first casting blanks in molds. With it he produced telescopic instruments of great focal lengths that were widely used.

Using his own instruments, Campani made significant astronomical observations of the satellites of Jupiter and of the rings of Saturn in 1664–1665 and published the results. Also interested in the microscope, he developed a screw-barrel type of instrument that could be made of metal or wood and permitted greater precision of adjustment than had previously been possible.

Campani was active in the production of lenses and optical instruments for more than fifty years. After his death the contents of his workshop in Rome were purchased by Pope Benedict XIV for the Istituto delle Scienze at Bologna. A substantial number of his clocks, telescopes, microscopes, and lenses are preserved in major collections, including the Istituto e Museo di Storia della Scienza in Florence, the Conservatoire National des Arts et Métiers and the Observatoire National in Paris, and the Medical Museum of the Armed Forces Institute of Pathology in Washington, D.C.

BIBLIOGRAPHY

I. Original Works. Campani’s writings are Discorso di Giuseppe Campani Intorno a Suoi’ muti Oriuoli, alle nuove Sfere Archimedee, e ad un ‘altra rarissima & Utilissima inventione di Personaggio cospicuo (Rome, 1660); Ragguaglio di Due Nuove Osservazioni Una Celeste in Ordine alla Stella di Saturno: e Terrestre l’altra in Ordine agli Strumenti Medesimi, co’quali si e Fatta l’una e l’altra Osservazione, dato al Serenissimo Principe Mattia di Toscana (Rome, 1664); and Lettera di Giuseppe Campani Intorno all’Ombre delle Stelle Medicee nel volto di Giove, ed altri nuovi Fenomeni Celesti scoperti co’suoi Occhiali, al Signor Gio: Domenico Cassini Primario Astronomo nell’inclito Studio di Bologna (Rome, 1665)

II. Secondary Literature. On Campani or his work, see S. A. Bedini, “Die Todesuhr,” in Uhrmacher and Goldschmied, no. 12 (1956); and “The Optical Workshop of Giuseppe Campani,” in Journal of the History of Medicine and Allied Sciences, 16 , no. 1 (1961), 18–38.

S. A. Bedini