Franz Xavier von Zach publishes Tables of the Sun (Gotha, 1792; new and improved edition, Gotha, 1804), and numerous papers on geographical subjects, particularly on the geographical positions of many towns and places, which he determines on his travels with a sextant.

Zach had studied physics at the Royal University of Pest, served for some time in the Austrian army, and taught at the University of Lemberg (now Lviv, Ukraine).

He lived in Paris in 1780–83, and in London from 1783 to 1786 as tutor in the house of the Saxon ambassador, Hans Moritz von Brühl.

In Paris and London he had entered the circles of astronomers like Joseph de Lalande, Pierre-Simon Laplace and William Herschel.

In 1786 he had been appointed by Ernest II, Duke of Saxe-Gotha-Altenburg, as director of the new observatory on Seeberg hill at Gotha, completed in 1791.