BROUNCKER

, or BROUNKER, (William), lord viscount of Castle Lyons in Ireland, son of Sir William Brounker, afterwards made viscount in 1645, was born about the year 1620. He very early discovered a genius for mathematics, in which he afterwards became very eminent. He was made doctor of physic at Oxford June 23, 1646. In 1657 and 1658, he was engaged in a correspondence by letters on mathematical subjects with Dr. John Wallis, who published them in his Commercium Epistolicum, printed 1658, at Oxford. He was one of the nobility and gentry who signed the remarkable declaration concerning king Charles the 2d, published in April 1660.

After the restoration, lord Brounker was made chancellor and keeper of the great seal to the queen consort, one of the commissioners of the navy, and inaster of St. Katherine's hospital near the tower of London. He was one of those great men who first formed the Royal Society, of which he was by the charter appointed the first president in 1662: which office he held, with great advantage to the Society, and honour to himself, till the anniversary election, Nov. 30, 1677. He died at his house in St. James's street, Westmin- ster, the 5th of April 1684; and was succeeded in his title by his younger brother Harry, who died in Jan. 1687.

Lord Brounker had several papers inserted in the Philosophical Transactions, the chief of which were, 1. Experiments concerning the Recoiling of Guns.— 2. — Series for the Quadrature of the Hyperbola; which was the first series of the kind upon that subject. —3. Several of his letters to archbishop Usher were also printed in Usher's letters; as well as some to Dr. Wallis, in his Commercium Epistolicum, above mentioned.