DITTON, HUMPHREY, an eminent divine and mathematician, was born at Salisbury May 29, 1675. Ho was an only son ; and manifesting good abilities for learning, his father procured for him en excellent private education. It does not appear that he was ever at either of the universities, a circumstance owing probably to the reli gious principle. dada parents. Contrary, it is understood, to his own inclination, but in conformity with his father's wishes, he chose the profession of theology ; and he filled a dissenting pulpit for several years at Tunbridge with great credit and usefulness. His constitution being delicate, and the restraints of his father's authority being removed—he also having married at Tnnbridge—he began to think of turning his talents into another channel. His mathematical attain ments having gained for him the friendship of Mr. Whiston and Dr. Harris, they made him known to Sir Isaac Newton, by whom he wail greatly esteemed, and by whose recommendation and influence ha was elected mathematical master of Christ's Hospital. This office he held during the rest of his life, which however was but short, as he died in 1715, in the rot tieth year of his age.
Ditton was highly esteemed amongst his friends ; and great expec tations were entertained that he would have proved one of the most eminent men of his time. Ho however attained a high degree of celebrity, and published several works and papers of considerable value, of which the following list contains the principal : 1. On the Tangents of Curves,' &c., 'Phil. Trans.,' vol. xxiii. 2. 'A Treatise on Spherical Catoptrica,' in the 'Phil. Trans.' for 1705; from whence it was copied and reprinted in tho ' Acta Eruditorum,' 1707. 3. ' General Laws of Nature and Motion,' 8vo, 1705. "%Volans men tions this work, and says that it illustrates and renders easy the writings of Galileo, Hnygena, and the 'Principia' of Newton. 4. 'An Institution of Fluxion', containing the first Principles, Operations, and Application. of that admirable Method. as invented by Sir Isaac Newton,' Svo, 1706. 5. In 1709 he published the ' Synopsis Alga brake' of John Alexander, with many additions and corrections.
6. His' Treatise on Perspective' was published in 1712. In this work he explained the principles of that art mathematically; and besides teaching the methods then generally practised, gave the first hints of the new method, afterwards enlarged upon and improved by Dr. Brook Taylor, and which was published in the year 1715. In 1714 Mr. Ditton published several pieces, both theological and mathematical, particu larly (7.) his Discourse on the Resurrection of Jesus Christ,' and (S.) the ' New Law of Fluids, or a Discourse concerning the Ascent of Liquid., in exact Geometrical Figures, between two nearly contiguous Surfaces.' To this was annexed a tract to demonstrate the impossi bility of thinking or perception being the result of any combination of the parte of matter and motion : a subject which was much agitated about that time. To this work was also added an advertisement from him and Mr. Whiston concerning a method for discovering the longi tude, which it seems they had published about half a year before. This attempt probably coat our author his life; for though it was approved and countenanced by Sir Isaac Newton before it was pre united to the Board of Longitude, and the method has since been aucceasfully put in practice in finding the longitude between Paris and Vienna, yet that board determined against it. The disappoint ment, together with some ridicule (particularly in some verses written by Dean Swift), so far affected his health, that he died in the ensuing year, 1715.
In the account of Mr. Ditton, prefixed to the German translation of his discourse on the Resurrection, it is said that he had published, In his own name only, another method for finding the longitude; but this Whiston denied. However, Raphael Levi, a learned Jew, who had studied under Leibnitz, informed the German editor that he well knew that bitten and Leibnitz had made a delineation of a machine which be had invented for that purpose, that it was a piece of mechanism constructed with many wheels like a clock, and that Leibnitz highly approved of it for land use, but doubted whether it would answer on shipboard, on account of the motion of the ship.