April 4: Joseph-Nicolas Delisle

Joseph-Nicolas Delisle

April 4, 1688 - 1768

Joseph-Nicolas Delisle was a French astronomer.

He was one of the 11 sons of Claude Delisle (1644-1720). Like many of his brothers, among them Guillaume Delisle, he initially followed classical studies. Soon however, he moved to astronomy under the supervision of J. Lietaud and Jacques Cassini.

He entered the French Academy of Sciences as pupil of Giandomenico Maraldi (1709-1788). Though he was a good scientist and member of a wealthy family he did not have much money.

His life changed radically when he was called by the Russian czar Peter the Great to Saint Petersburg to create and run the school of astronomy. He arrived there only in 1726, after the death of the czar. He became quite rich and famous, to such an extent that when he returned to Paris in 1747, he built his own observatory in the palace of Cluny, later made famous by Charles Messier. Also he received the title of Astronomer from the Academy.

Delisle is mostly known for the Delisle scale, a temperature scale he invented in 1732.

The Lunar crater Delisle and the asteroid 12742 Delisle are named in his honor.