Page:Dictionary of National Biography volume 15.djvu/76

 DIGGES, DUDLEY (1613–1643), political writer, third son of Sir [q. v.], was born at Chilham, Kent, in 1613. He entered University College, Oxford, in 1629, proceeded B.A. on 17 Jan. 1632, M.A. on 15 Oct. 1635. In 1633 he was elected fellow of All Souls. In September 1642 he is mentioned as one of a ‘delegacy’ appointed to provide means for defending Oxford against the parliament during the civil war (, History and Antiquities of the University of Oxford, ed. Gutch, ii. 447). He died at Oxford on 1 Oct. 1643 of the malignant camp fever then raging there, and was buried in the outer chapel of All Souls. Digges was a devoted royalist, and all his important writings were in defence of Charles I. His works were:
 * 1) ‘Nova Corpora Regularia,’ 1634. This is a demonstration of certain mathematical discoveries made about 1574 by his grandfather, Thomas Digges.
 * 2) ‘An Answer to a Printed Book intituled Observations upon some of His Majestie's late Answers and Expresses,’ Oxford, 1642.
 * 3) ‘A Review of the Observations upon some of His Majestie's late Answers and Expresses,’ York, 1643.
 * 4) ‘The Unlawfulnesse of Subjects taking up arms against their Soveraigne in what case soever,’ 1643. This defence of the doctrine of passive obedience was widely popular among the royalists and went through several editions.

 DIGGES, LEONARD (d. 1571?), mathematician, was the son of James Digges of Digges Court, in the parish of Barham, Kent, by Philippa, his second wife, daughter of John Engham of Chart in the same county. The family was an ancient and considerable one. Adomarus Digges was a judge under Edward II; Roger served in three parliaments of Edward III; James Digges was a justice of the peace many years, and sheriff in the second of Henry VIII. He left Digges Court to his eldest son John, and the manor of Brome to Leonard, who sold it, and purchased in 1547 the manor of Wotton, likewise in Kent, where he resided. We hear of an act passed in the fifth year of Elizabeth ‘for the restitution of Leonard Digges,’ but it is not printed among the statutes. He married Bridget, daughter of Thomas Wilford of Hartridge, Kent, and had by her [q. v.], a distinguished mathematician, and the editor of several of his works. The elder Digges died about 1571. He studied at University College, Oxford, but took no degree, though his ample means and leisure were devoted to scientific pursuits. He became an expert mathematician and land surveyor, and (according to Fuller) ‘was the best architect in that age, for all manner of buildings, for conveniency, pleasure, state, strength, being excellent at fortifications.’ Lest he should seem to have acquired knowledge selfishly, he printed in 1556, for the public benefit, ‘A Booke named Tectonicon, briefly showing the exact measuring, and speedie reckoning all manner of Land, Squares, Timber, Stone, etc. Further, declaring the perfect making and large use of the Carpenter's Ruler, containing a Quadrant geometricall; comprehending also the rare use of the Square.’ The next edition was in 1570, and numerous others followed down to 1692. The author advised artificers desirous to profit by this, or any of his works, to read them thrice, and ‘at the third reading, wittily to practise.’

A treatise, likewise on mensuration, left in manuscript, was completed and published by his son in 1571, with the title, ‘A Geometricall Practise, named Pantometria, divided into Three Bookes, Longimetria, Planimetria, and Stereometria, containing Rules manifolde for Mensuration of all Lines, Superficies, and Solides.’ The first book includes a very early description of the theodolite (chap. xxvii.), and the third book, on Stereometry, is especially commended for its ingenuity by Professor De Morgan. In the dedication to Sir Nicholas Bacon, Thomas Digges speaks of his father's untimely death, which was then apparently a recent event, and of the favour borne to him by the lord keeper. A second revised edition was issued in 1591. The twenty-first chapter of the first book includes a remarkable description of ‘the marvellous conclusions that may be performed by glasses concave and convex, of circular and parabolical forms.’ He practised, we are there informed, the ‘multiplication of beams’ both by refraction and reflection; knew that the paraboloidal shape ‘most perfectly doth unite beams, and most vehemently burneth of all other reflecting glasses,’ and had obtained with great success magnifying effects from a combination of lenses. ‘But of these conclusions,’ he added, ‘I mind not here more to intreat, having at large in a volume by itself opened the miraculous effects of perspective glasses.’ The work in question never was made public. Especially he designed to prosecute, after the example of Archimedes, the study of burning-glasses, and hoped to impart secrets ‘no less serving for the security and defence of our natural country, than surely to be marvelled at of strangers.’ The assertion that