On September 19, 1749, Jean Baptiste Joseph Delambre was born in Amiens (France). He made observations of the planet Uranus, identified by Herschel in 1781, in order to verify theoretical results of Laplace. Delambre is also known for the formula in spherical trigonometry that bears his name (1807). Delambre died on August 19, 1822, in Paris. More information can be found here.