Audiffredi, John Baptist

, an able astronomer and mathematician, was born at Saorgio, near Nice, in Provence, in 1714. At the age of sixteeeri he entered the order of St. Dominic, and made rapid progress in his studies, not only in sacred literature, but in mathematics, and the languages. In his thirty-fifth year he was | appointed second librarian of the Casanata, and ten years aftenvards first librarian, which office he held until his death. His studies were extended to mathematics, astronomy, antiquities, natural history, criticism, and bibliography but astronomy was his favourite pursuit, on which he published many pieces. He was appointed by the late pope Pius VI. to make mineralogical observations on the new mines of Tolfa. He died July 3, 1794. His published works are, 1. “Mercurius in sole visus, observatio habita Romae, &c.Rome, 1753, 4to. 2. “Phenomena ccelestia observata,Rome, 1754, 8vo. 3. “Otia astronomica,Rome, 1755, 4to. 4. “Novissimus Mercurii transitus,Rome, 1756, 8vo. 5. “Passaggio di Venere, &c.” 4to, without place or date, but most probably 1761. 6. “Transitus Veneris, &c.1762. This appears to be cither the same work as the preceding, or a Latin translation. 7. “Investigatio Parallaxis Solaris, &c.Rome,. 1765, 8vo, published under the anagrammatical name of Dadeus Ruffus. 8. “De Solis Parallaxi commentarius,Rome, 1766, 8vo. 9. “Dimostrazione della theoria, &c.” of the Comet of the year 1769, published in a literary journal at Rome, 1770. 10. “Letere typografiche,” under the name of the abbe Nicolas Ugolini de Foligno, addressed to Xavier Laire, author of the historical essay on the Roman typography of the 15th century, Mentz, 1778, 8vo, a satirical attack on father Laire. 11. “Catalogus historico-criticus Romanarum editionum saeculi 15.Rome, 1783, 4to. 12. “Catalogus librorum typis impressorum bibliothecae Casanatensis, praestantioribus notis et observationibus illustratus,” 4 vols. fol. 1762, 1768, 1775, 1788. 13. “Specimen historico-criticum editionum Italicarum ssGCuli 15,Rome, 1794, 4to. In some of the foreign journals, are other essays by him on astronomical subjects. 1