Ditton, Humphrey

, an eminent mathematician, was born at Salisbury, on the 29th of May, 1675, being the fourteenth of that name in a direct line. His father was a gentleman possessed of a small estate in the county of Wilts. His mother was of the family of the Luttrells of Dunstercastle, near Taunton, in Somersetshire, whose fortune made a considerable increase to the family income. Mr. Ditton’s father being of the sect of nonconformists, and extremely tenacious of his opinions, entered much into the religious controversifs of those times, and in supporting such contentions impaired his fortune, almost to the ruin of his family. Mr. Humphrey Ditton was the only son; and his father, observing in him an extraordinary good capacity, was desirous that he should not want the advantage of a good education. Accordingly, he placed him in a private academy, under the direction of Dr. Olive, a clergyman of the established church, who, notwithstanding his religious sentiments were different from those of Mr. Ditton’s family, was much esteemed by them for his candour and moderation in those troublesome times. When Mr. Ditton had finished his studies under Dr. Olive, he at the desire of his father, although contrary to his own inclination, engaged in the professioa of divinity, and began to exercise his function at Tunbridge, in Kent, where he continued to preach some years during which time he married Miss Ball, a lady at that place.

He was so indefatigable and assiduous in the exercise of his calling, that he very much impaired his health; so | that several of his friends foreseeing it would shorten his life, advised him to relinquish a profession which the weakness of his constitution could not support. These circumstances, together with the death of his father, which happened about the same time, determined him to quit the profession of divinity and at the persuasion of Dr. Harris and Mr. Whiston, both eminent mathematicians, he engaged in the study of mathematics, to which he had always a great propensity. In the prosecution of this science he was much encouraged by the success and applause he received. He was highly esteemed by sir Isaac Newton, by whose interest and recommendation he was elected master of the new mathematical school in Christ’s hospital, in which office he remained during his life.

Mr. Ditton published many mathematical and other tracts. His first works were a paper on the Tangents of Curves, and a treatise on Spherical Catoptrics, both which were published in the “Philosophical Transactions.” This last was written in the Latin language, and was so highly approved, that it was republished in a foreign periodical work, called the “Acta Eruditortim,” in 1707; and was afterwards printed in the “Memoirs of the Academy of Sciences at Paris.” In 1706 he published a treatise, entitled, “An Institution of Fluxions, containing the first principles, operations, and applications of that admirable method, as invented by sir Isaac Newton.” This work, with additions and alterations, was again published by Mr. John Clarke, in 1726, some years after Mr. Ditton’s death. The same year, 1 706, Mr. Ditton also published a treatise on the laws of nature and motion. Of this the celebrated Wolfius makes mention, and asserts, that it illustrates and renders easy the writings of Galileo, Huygens, and the “Principia” of sir Isaac Newton. It is also noticed by De la Roche, in “The Memoiresde Literature,” vol. VIII. p. 46. In 1709 he published the “Synopsis Algebraicum” of John Alexander Bernatus Helvetius; with many additions and corrections. 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 afterward enlarged upon and improved by Dr. Brook Taylor; and which was published in 1715. Several publications of Mr. Ditton’s appeared in 1714, one of which was a “Discourse upon the Resurrection of Jesus Christ;| the truth of which he here endeavoured to demonstrate. This work went through four editions, and was translated into several of the modern languages. Tindal, Collins, and some other authors, opposed it, and endeavoured to confute the reasoning; to whom Ditton had begun an answer, but died before it was finished; and his friends, upon revising it, found it too incomplete to hazard its publication. Another of his works that appeared in the same year, was, “The new law of Fluids; or, a Discourse concerning the ascent of liquids, in exact geometrical figures, between two nearly contiguous surfaces.” To this was annexed a tract, to demonstrate the impossibility of thinking or perception being the result of any combination of the parts of matter and motion; a subject much agitated in those days by the free-thinkers and their opponents. There was also adjoined to this work an advertisement from him and Mr. Whiston, concerning a method for discovering the longitude; which, it appears, they had published about half a year before. This attempt, it is thought, cost Mr. Ditton his life; for, although it was approved and countenanced by sir Isaac Newton, previously to its being presented to the Board of longitude, and the method lias been since successfully put in practice, in finding the longitude between Paris and Vienna, yet that board then determined against it. Such a disappointment, together with the public ridicule incurred, is supposed to have affected his health, but this we think unlikely, as his death was occasioned by a putrid fever, which proved fatal Oct. 15, 1715, in the fortieth year of his age. He was much regretted by the philosophical literati of that time, who expected from his assiduity, learning, and penetrating genius, many useful and ingenious discoveries.*

*

Doctor Arbuthnot, in a letter to dean Swift, dated July 17, 1714, says, “Whiston has at last published his project of the longitude; the most ridiculous thing that ever was thought on. But a pox on him, he has spoilt one of my papers of Scriblerus, which was a proposal for the longitude, not very unlike his, to this purpose; that, since there was no pole for east and west, all the princes of Europe should join and built two prodigious poles, upon high mountains, with a vast lighthouse, to serve for a pole-star. I was thinking of a calculation of the time, charges, and dimensions. Now you must understand, his project is by light-houses, and explosions of bombs at a certain hour.” Absurd, however, as this might appear to the wits of the day, Whiston’s plan was the cause of an act being passed in the British parliament, allowing 2000l. towards making experiments; and also offering a reward to the person who should discover the longitude at sea, proportioned to the degree of accuracy that might be attained by such discovery; viz. a reward of 10,000l. if it determines the longitude to one degree of

|

a great circle, or 60 geographical miles; 15,000l. if it determines the same to two-thirds of that distance; and 20.000l. if it determines it to half that distance; with other regulations and encouragements.

| In an 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 which Mr. Whiston denied.*
*

So in the Biographia Britannica, which does not give us the date of this German translation. There was a German translation published in 1720, by Cornelius Coorn, which might have a life of Ditton prefixed to it, but in 1746, Whiston informs us that he wrote a life of his friend, to be prefixed to a German edition then in the press, and in which he would not have asserted what is here contradicted.

However, Raphael Levi, a learned Jew, who bad studied under Leibnitz, informed the German editor that he well knew that Ditton and Leibnitz hud corresponded upon the subject; and that Ditton had sent to Leibnitz a delineation of a machine he had invented that purpose; which was a piece of mechanism con with many wheels, like a clock, and which Leibnitz highly approved of for land use, but doubted whether it wouldanswer on ship-board, on account of the motion of the ship.

Mr. Ditton was buried in the cloisters of Christ’s-hospital, on the north side of the quadrangle, and near the passage at its east end. A large blue grave-stone, with a Latin inscription cut in it, was laid over the grave. The stone yet remains; but the inscription is entirely effaced. From a private diary of Mr. Ditton’s, he appears to have been a man of warm piety and simplicity of heart. His son, the rev. John Ditton, was many years lecturer of St. Mary’s, Islington, where he died March 16, 1776. 1

1

Biog. Brit. Whiston’s Memoirs. Gospel Magazine, by Vallance and Simmons, for 1777, where are many extracts from his Diary.