Franz Zach, baron, a German astronomer, born in Presburg in June, 1754, died in Paris, Sept. 2, 1832. He served in the Austrian army, was director of the observatory at Seeberg near Gotha from 1787 to 1806, accompanied the widowed duchess of Saxe-Gotha in a journey in France in 1804-'5, removed to the south of France in 1812, and went with the duchess to Italy in 1813, settling at Genoa, where they remained till her death in 1827, when he returned to France. His Geographische Ephemeriden and Monatliche Correspondenz (28 vols., Gotha, 1800-13) he continued while in Italy under the title of Correspondance astronomique (1818-'28). He also wrote on the attraction of mountains, and published several series of astronomical tables. He promoted the establishment of observatories at Naples and Lucca. - His elder brother, Baron Anton (1747-1826), was an Austrian general, reaching the rank of field marshal lieutenant in 1801. He published works on fortification and on tactics, and papers on mathematics and astronomy.