Person: De Tilly, Joseph Marie

Joseph Tilly was a Belgian soldier who published works on non-Euclidean geometry.

Tilly studied the principles of geometry, Euclid's fifth postulate and non-euclidean geometry without being aware that this had become a major topic of interest.
It was only in 1866 that he learnt about the work of the famous Russian mathematician on non-euclidean geometry, then in 1870 Tilly published a work Études de méchanique abstraite on Lobachevsky space.
Until this point Tilly had worked in isolation and it is certainly worth emphasising just how much harder this had made his research.
It was also made more difficult by the fact that Tilly did not have easy access to library material which is so necessary in order to write an authoritative historical work.
There were complaints that Tilly had unduly emphasised the scientific education of future officers at the École Militaire.
An inspector at the military school declared that Tilly was not allowed to use differentials, and that he must cease immediately from any mention of the infinitely small.
Tilly must have carried on with his methods of teaching calculus despite these warnings and as a consequence he was dismissed from his post and forced into early retirement in August 1900.

Born 16 August 1837, Ypres, Belgium. Died 4 August 1906, Munich, Germany.

View full biography at MacTutor

Origin Belgium

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

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