DIGGES, THOMAS, tho only eon of Leonard Digges. He was educated by his father with great care, and afterwards at Oxford, where he much distinguished himself; nud ultimately became one of the first mathematicians of his age.
He chose the military profession, and was appointed muster-master general to the forces sent out by Queen Elizabeth to succour the oppressed inhabitants of the Netherlands. Of his military career however no other evidence is known to exist except his writings on the subject. These prove that he must have given considerable attention to the details of his profession, and therefore have been a considerable period in active service. He died in 1595. The following is a list of his published writings, independently of editing his father's works :-1. ' Abe aive Scala) Mathematicie,' 4to, 1573: a curious work. 2. 'A Letter on Parallax,' printed in Dee's 'Parallacticse Comments tionis praxeosque nucleus quidam,' 4to, 1573. 3. ' An Arithmetical Military Treatise, containing so much of arithmetic as is necessary towards military discipline,' 4to, 1579. 4. ' 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 moderno militairo discipline, offices, laws, and orders in every well-governed camps and armie, inviolably to be observed,' 4to, 1590. 5. 'A brief and true Report of the proceedings of the Earl of Leycester, for the Relief of the town of Sluice, from his arrival at Vliahing, about the end of June 1537, untill the surrender thereof, 26 Julii ensuing, whereby it 312011 plalnlio appear his excellencio was not in anie fault for the surrender of that towns :' published with the last, 1590. 6. ' A brief
Discourse what orders were best for repulsing any forraine forcer', if at anie time they should invade us by sea in Kent or elsewhere :' published with the two last, 1590. 7. ' A perfect Description of the Celestial Orbs according to the most ancient doctrine of the Pythago reans.' This was published as a supplement to his edition of his father's ' Prognostication Everlasting,' 4to, 1592. 8. ' A humble Motive for Association to maintain the Religion Established,' 8vo, 1601. To this is added a letter to the archbishops and bishops to enforce tbe same object. 9. 'England's Defence ; or a treatise con cerning invasion :' written in 1599, but not published. It is essen tially a eccond edition of the tract already spoken of in the Stratioticos.
Digges wrote many other works, which he left in manuscript, and which were never published, on account, it is stated, of the perplexity created by lawsuits in which he was engaged. The accomplished politician and elegant writer, SIR DUDLEY DIGGES (born 1583, died 1639), was the eldest son of Thomas Digges. The work by which he is chiefly remembered is the collection of letters which passed between the ministers of Elizabeth respecting her projected marriage with the Due d'Anjon, and which was published after his death (1655), under the title of the ' Compleat Ambassador.'