20 October

1896: On 20 October 1896, Félix Tisserand died.

Tisserand was a French astronomer especially noted for his textbook Traité de mécanique céleste ('Treatise on Celestial Mechanics'). This work, an update of Pierre-Simon Laplace's work on the same subject, is still referred to by current writers of celestial mechanics books.

From 1892 until his death he was director of l'Obseratoire de Paris (Paris Observatory)