Jean Théophile, D.D., a distinguished philosopher and mechanician, was born at Rochelle, March 12, 1683, and brought to England whilst yet an infant by his father, who was a French Protestant minister, and had left his native country at the revocation of the edict of Nantes. He received his education at Christ-Church, Oxford, where he ultimately succeeded Dr Keil in reading lectures on experimental philosophy at Hart-Hall. Dr Desaguliers became chaplain to the Duke of Chandos, who presented him to the living of Edgeware; and he afterwards was made chaplain to Frederick Prince of Wales. He continued to read lectures with great success till his death in 1749. To the Philosophical Transactions he communicated many curious papers. He also published a valuable Course of Experimental Philosophy, in 2 vols. 4to; and gave to the world an edition of Gregory's Elements of Catoptries and Dioptries, with an appendix on reflecting telescopes, 8vo. He was a member of the Royal Society, and of several foreign academies. The following lines of the poet Cawthorn depict the indigence and neglect into which he fell in his old age:

How poor, neglected, Desaguliers fell! How he who taught two gracious kings to view All Boyle ennobled, and all Bacon knew, Died in a cell, without a friend to save, Without a guinea, and without a grave.