This day in French history.
Today is the day of the birth of Joseph-Nicolas Delisle. He studied astronomy under Joseph Lieutaud and Jacques Cassini.
Later, he was called upon to run the School of Astronomy for Czar Peter the Great in St. Petersburg, Russia.
When he returned to Paris in 1747, he built an observatory in the Palace of Cluny.
In 1732 he developed the Delisle temperature scale.
A crater on the Moon and Asteroid 12742 are named after him.