Joseph-Nicolas Delisle

Joseph-Nicolas Delisle (1688 to 1768) was a French astronomer and cartographer, best known for the Delisle temperature scale that he invented in 1732. Born in Paris as one of the eleven sons of Claude Delisle, he moved from classical studies to astronomy under Joseph Lieutaud and Jacques Cassini and in 1714 entered the French Academy of Sciences as a pupil of Giacomo Filippo Maraldi. He set up an observatory at the Luxembourg Palace in 1712, met Edmond Halley in London in 1724 and in 1725 was called by Peter the Great to Saint Petersburg to create and run a school of astronomy, arriving in 1726. There he prepared a map of the known North Pacific that was used by Vitus Bering, and in 1740 he led an expedition to Siberia to observe a transit of Mercury from Beryozovo. Back in Paris in 1747 he built a new observatory in the palace of Cluny, later made famous by Charles Messier. He was elected a Fellow of the Royal Society in 1725 and a foreign member of the Royal Swedish Academy of Sciences in 1749, and in 1760 he proposed a coordinated international observation of the 1761 transit of Venus.