LEONARD**, an able mathematician in the sixteenth century, was born at Digges Court, in the parish of Barham, Kent, and was educated at Oxford. He was the author of the following works: viz., *Tectonicum, briefly showing the exact Measuring and speedy Reckoning of all manner of Lands, Squares, Timber, Stones, Steeples, &c.*, 1556, 4to; a geometrical practical treatise, named *Pantometria*, in three books, published posthumously by his son in 1591; and *Prognostication Everlasting of right good effect, or Choice Rules to judge the Weather by the Sun, Moon, and Stars*, &c., 4to, 1555, 1556, and 1564; afterwards corrected and augmented by his son, 4to, 1592. Digges died about 1574.

THOMAS**, only son of the preceding, and one of the ablest mathematicians of his age. He was sent by Queen Elizabeth as master-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 raising, correcting, and enlarging some of his father's works, he wrote *Algebra seu Mathematica*, *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 Stratificos, requisites for the perfection of Soldiery*, 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 motion 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's England's Defence; or, a Treatise concerning Imagination, a trait of the human nature so that printed at the end of his Stratificos, and called a *Brief Discourse*, &c., but not published till 1686; A letter printed before Dr John Dee's *Mathematical Demonstrations praecipue unusquisque quidem*, 1573, 4to. Besides these and his *New Corpora*, he left several mathematical treaties ready for the press, which, by reason of law-suits and other engagements, he was prevented from publishing.