BLONDEL (Francis)

, a celebrated French mathematician and military engineer. He was born at Ribemond in Picardy in 1617. While he was yet but young, he was chosen Regius Professor of Mathematies and Architecture at Paris. Not long after he was appointed governor to Lewis-Henry de Lomenix, Count de Brienne, whom he accompanied in his travels from 1652 to 1655, of which he published an account. He enjoyed many honourable employments, both in the navy and army; and was entrusted with the management of several negociations with foreign princes. He arrived at the dignity of marshal de camp, and counsellor of state, and had the honour to be appointed mathematical preceptor to the Dauphin. He was a member of the Royal Academy of Sciences, director of the Academy of Architecture, and lecturer to the Royal College: in all which he supported his character with dignity and applause. Blondel was no less versed in the knowledge of the Belles Lettres than in the mathematical sciences, as appears by the comparison he published between Pindar and Horace. He died at Paris the 22d of February 1686, in the 69th year of his age. His chief mathematical works were,

1. Cours d'Architecture. Paris, 1675, in folio.

2. Resolution des quatre principaux problemes d'Architecture. Paris, 1676, in folio.

3. Histoire du Calendrier Romain. Paris, 1682, in 4to. |

4. Cours de Mathematiques. Paris, 1683, in 4to.

5. L'Art de jetter des Bombes. La Haye, 1685, in 4to.

Besides a New Method of fortifying Places, and other works.

Blondel had also many ingenious pieces inserted in the Memoirs of the French Academy of Sciences, particularly in the year 1666.