Jesuit missionary, mathematician, and reformer of the Chinese calendar; b. Milan, Italy, Jan. 29, 1592; d. Beijing, China, April 27, 1638. Rho entered the Society of Jesus Aug. 24, 1604, and was ordained by Cardinal Robert Bellarmine at Rome. He taught mathematics at Milan until his departure for the Far East in 1620 with 44 companions. His arrival at Macau coincided with an attack on the city by the Dutch, who were driven off by artillery directed by Rho. In 1624 he entered China and soon gained a firm command of the language. His religious writings in Chinese embraced such topics as fasting, the corporal works of mercy, and prayer. In 1631 his knowledge of mathematics led to his being appointed to the Imperial Bureau of Astronomy in Beijing where he labored with Father Johann Adam schall von bell on the calendar reform until his death. Rho's contribution to this vast project was some 17 tracts on astronomical subjects. His work was in the tradition of Father Matteo ricci, who hoped to convert the Chinese to Christianity by the means of science.
Bibliography: c. sommervogel et al., Bibliothéque de la Compagnie de Jésus (Brussels–Paris 1890–1932) 6:1709–18; 9:803–804. l. pfister, Notices biographiques et bibliographiquessur les Jésuites de l'ancienne mission de Chine 1552–1773 (Shanghai 1932–34) 1:188–191.
[j. v. mentag]