KEILL, Jonx, a celebrated mathematician and natural philosopher, was born at Edinburgh in the year 1671, and studied in that university under the celebrated Dr. Grego ry. In 1694, he entered Baliol College, Oxford, where he acquired considerable reputation, by reading private lec tures on experimental philosophy. He succeeded Dr. Mil lington in 1700. as Sedlcian professor of natural philosophy. In 1708 he was elected a fellow of th. Royal Society. In 1709, he went to New England, as treasurer to the Pala tines, and upon his return in 1710, he was chosen Sivilian professor of astronomy in Oxford. About the }ear 1711, he was by Queen Anne. decypherer to her ma jesty, an office which he held till 1716. Having been seiz ed with a violent fever, he died on the 1st September 1721, in the 50th year of his age. The following is a list ol the principal works of Dr. Keill : An Examination of Dr Burnet's Theory of the Earth, with sonie remarks on Mr. ll'histon's NeRll Theory of the Earth. Lond. 1698. A second edition of this work ap peared in 1737.
Introductio ad lreranz Phyaicant. Lond. 1702. A new edition or it appeared in 1736 An edition of Euclid, with too tracts on Trigonometry, and the nature of logarithms, 1713.
Introductioad Verain .1stronomiani, in 1701, which was afterwards translaterf into English.
His papers in the Philosophical Transactions, are, 1. On the Laws of Attraction, and Physical Princi ples. Phil. Trans. 170e, No. 313, p. 97 2 Of the Laws of Centrifugal Force, 17..8. No. 317.p. i 74.
3. The Newtonian Solution of Kepler's Problem of find ing the true motion of the Planets, &c. &c. 1713. No. 337. p. 1.
4. Theoremata qumdam infinitam materize divisibilita tem spectantia, 1714. No. 337. p. 82.
5. Onservations on Mr. John Bernoulli's remarks on the inverse problem of Centripetal Forces, with a new solution of the Problems, 1714. No. 350. p. 91.
See our life of Joax BERNOULLI, for an account of our author's quarrel with that mathematician ; and our article FrusioNs, for an account of his dispute with Leibnitz.