Person: Boulliau, Ismael

Ismael Boulliau was a French clergyman and amateur mathematician who proposed an inverse square law for gravitation before Newton.

He is the Ismael Boulliau of this biography.
There was in Loudun an important circle of intellectuals of which Ismael Boulliau Senior was part.
It was important for the young Ismael who attended these meetings and became acquainted with many leading men of the day.
Boulliau was brought up a Calvanist by two Calvanist parents.
It had been catalogued in 1622, ten years before Boulliau arrived in Paris, and Pierre and Jacques Dupuy travelled throughout France amassing books and manusctripts for the library.
In his capacity as librarian Boulliau travelled widely in Italy, Holland and Germany buying books.
Boulliau was a friend of Pascal, Mersenne and Gassendi and supported Galileo and Copernicus.
In 1645 Boulliau published Astronomia philolaica Ⓣ(The astronomy of Philolaus) which accepts elliptical orbits for planets.
There is one aspect of Boulliau's philosophy which is well worth commenting on - namely the fact that he believed in simple explanations and moreover he wanted many different observed properties to result from a single cause.
Boulliau was a close associate of Huygens who turned to him first with his discovery of the rings of Saturn and sent him pendulum clocks.
One of the most interesting aspects for modern research into Boulliau, however, is that he was a prolific correspondent.

Born 28 September 1605, Loudun, France. Died 25 November 1694, Paris, France.

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Astronomy

Thank you to the contributors under CC BY-SA 4.0!

O’Connor, John J; Robertson, Edmund F: MacTutor History of Mathematics Archive