Jacques-André Mallet

Jacques-André Mallet, also called Mallet-Favre, was a Genevan mathematician and astronomer, born in Geneva on 23 September 1740 and dead on 31 January 1790. Disabled by a childhood burn, he gave up his father's plan of a military career and joined the Academy of Geneva in 1755, where he learned from the mathematician Louis Necker, then studied in Basel under Daniel Bernoulli and finished in 1762. Invited to Russia by Catherine the Great, he travelled to Ponoy in Lapland to observe the 1769 transit of Venus, though rain hid most of it, and his data on solar parallax still proved useful. Back in Geneva he founded the city's first observatory in 1772, co-financed it, and directed it until his death. His research dealt with occultations, lunar and solar eclipses, sunspots, planetary orbits and the orbits of the moons of Jupiter, and he kept a long diary of weather and farming at his estate in Avully.