DIGGES, THOMAS, only son of the preceding, and one of the ablest mathematicians of his age. He was sent by Queen Elizabeth as muster-master-general of the British forces in the Netherlands, and thus acquired an extensive and accurate knowledge of military affairs. He died in 1595.
Besides revising, correcting, and enlarging some of his father's works, he wrote Alcive five Scales Mathematicæ, or Mathematical Wings or Ladders, 1573, 4to; An Arithmetical Military Treatise, containing so much of Arithmetic as is necessary towards military discipline, 1579, 4to; A Geometrical Treatise, named Stratiotics, requisite for the perfection of Soldiers, 1579, 4to; A perfect Description of the Celestial Orbs, according to the most ancient doctrine of the Pythagoreans, &c., placed at the end of his father's Prognostication Everlasting, printed in 1592, 4to; A humble motive 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; England's Defence, or, a Treatise concerning Invasion, a tract of the same nature with that printed at the end of his Stratiotics, and called a Brief Discourse, &c., but not published till 1685; A letter printed before Dr John Dee's Parallaxica Commentationis praeclarior nucleus quidam, 1573, 4to. Besides these and his Nova Corpora, he left several mathematical treatises ready for the press, which, by reason of law-suits and other engagements, he was prevented from publishing.