Ernest Esclangon

Looking for some means of financial support while he completed his doctorate on quasi-periodic functions, he took a post at the Bordeaux Observatory, teaching some mathematics at the university.

During World War I, he worked on ballistics and developed a novel method for precisely locating enemy artillery.

He is perhaps best remembered for initiating in 1933 the first speaking clock service, reportedly to relieve the observatory staff from the numerous telephone calls requesting the exact time.

Esclangon was the President of the Société astronomique de France (SAF), the French astronomical society, from 1933–1935.

His doctoral students include Daniel Barbier, Édmée Chandon, Louis Couffignal, André-Louis Danjon, and Nicolas Stoyko.