Digges, Thomas

, only son of the preceding Leonard Digges, after a liberal education at home, studied for some time at Oxford; and partly by the improvements he made there, and the previous instructions of his learned father, became one of the greatest mathematicians of his age. Of his history, however, we only know that when queen Elizabeth sent some forces to assist the oppressed inhabitants of the Netherlands, he was appointed muster-­master general, by which he hud an opportunity of becoming skilled in military affairs. The greater part of his life must have been spent in his favourite studies, as besides the revising, correcting, and enlarging some pieces of his father’s, already mentioned, he wrote and published the following learned works himself: 1. “Alæ sive scalæ mathematicæ; or mathematical wings or ladders,” 1573, 4to; containing several demonstrations for finding the parallaxes of any comet or other celestial body; with a correction of the errors in the use of the radius astronomicus. 2. “An arithmetical military treatise, containing so much of arithmetic as is necessary towards military discipline,” 1579, 4to. 3. “A geometrical treatise, named Stratioticos, requisite for the perfection of soldiers,” 1579, 4to. This was begun by his father, but finished by himself. They were both reprinted together in 1590, with several amendments and additions, under this title: “An arithmetical warlike treatise, named Stratioticos; compendiously teaching the science of numbers, as well in fractions as integers, and so much of the rules and equations algebraical, and art of numbers cossical, as are requisite for the profession of a souldier. Together with the moderne militaire discipline, offices, lawes, and orders in every well-governed campe and armie, inviolably to be observed.” At the end of this work there are two pieces; the first entitled “A briefe and true report of the proceedings of the earle of Leycester, for the reliefe of the towne of Sluce, from his arrival at Vlishing, about the end of June 1587, untill the surrendrie thereof, 26 Julii next ensuing. Whereby it shall plainlie appear his excellencie | was not in anie fault for the losse of that towne;” the second, “A briefe discourse what orders were best for repulsing of foraine forces, if at any time they should invade us by sea in Kent, or elsesvhere.” 4. “A perfect description of the celestial orbs, according to the most ancient doctrine of the Pythagoreans,” &c. This was placed at the end of his father’s “Prognostication everlasting, &c.” printed in 1592, 4to. 5, “Humble motives for association to maintain the religion established,” 1601, 8vo. To which is added, his “Letter to the same purpose to the archbishops and bishops of England.” 6. “England’s Defence; or a treatise concerning invasion.” This is a tract of the same nature with that printed at the end of his Stratioticos, and called, “A briefe discourse,” &c. It was written in 1599, but not published till 1686. 7. A letter printed before Dr. John Dee’s “Parallaticce commentationis praxeosque nucleus quidam,” 1573, 4to. Besides these and his “Nova Corpora,” he had by him several mathematical treatises ready for the press; but lawsuits, which probably descended upon him with his patrimony, and were productive of pecuniary embarrassments, broke in upon his studies, and embittered his days. He died Aug. 24, 1595, and was buried in the chancel of the church of Aldermanbury, London. Among his unpublished works, was a Plan for the improvement of the Haven and Mole of Dover, in 1582, which was communicated to the Society of Antiquaries, and is printed in the “Archaeologia,” vol. XI. He married Agnes, daughter of sir William St. Leger, knt. ¹