by Stephen Johnston
© Oxford University Press 2004 All rights reserved
Digges, Thomas (c.1546-1595), mathematician and member of parliament, was the eldest son of Leonard Digges (c.1515-c.1559), practical mathematician, and his wife, Bridget, daughter of Thomas Wilford of Hartridge, Kent. Digges was presumably brought up on his father's estate at Wootton, Kent, but Leonard's land and property were seized after his involvement in the Wyatt uprising of 1554. Condemned to death for high treason, Leonard was pardoned and subsequently recovered his lands, but his sons lost their right of inheritance. Thomas Digges and his younger brother James were restored in blood by act of parliament only in 1563. In the interim their father had died and Thomas Digges's education was taken over by John Dee; Digges would later refer to Dee as his 'revered second mathematical father' (Alae seu scalae mathematicae, 1573, sig. A2r) and Dee considered Digges as 'my most worthy mathematical heir' (Dee, sig. A2v).
The combination of filial duty and the unusually mathematical nature of Digges's upbringing helps to explain the character of much of his published work. His first publication was Pantometria (1571), an edition of a manuscript on surveying and practical geometry by his father. Appended to this text was Digges's own contribution, A Mathematicall Discourse of Geometricall Solids. This was the most self-consciously advanced and novel work on geometry published in sixteenth-century England. Digges provided several hundred theorems on the properties, dimensions, and interrelations of the five regular (Platonic) polyhedra, and the final section of his text extended the enquiry to an investigation of five 'transformed' bodies--semi-regular (Archimedean) solids generated by the metamorphosis of each of the five Platonic solids.
The elevated level of Digges's work was confirmed by Alae seu scalae mathematicae (1573), a text prompted by the appearance of the new star of 1572. Addressed to a European audience of astronomers, Alae was Digges's only Latin publication and offered an analysis and improvement of the mathematical and instrumental techniques available for the study of the nova. Recent radio astronomy has shown that Digges's observations were the most accurate then made. Moreover, he concluded that the new star was indeed a celestial body rather than a meteorological phenomenon, thus challenging the interpretations offered by contemporary Aristotelian natural philosophy.
Digges's cosmological ambitions went beyond his claims concerning the new star. In Alae he condemned the 'monstrous' planetary astronomy of Ptolemy and wrote approvingly of Copernicus (Alae, sigs. A4v, 2A3r, 2A4v, L2v). But he did not wholeheartedly endorse the Copernican heliocentric system, in which the sun rather than the earth is stationed at the centre of the universe. Writing only shortly after the appearance of the new star, Digges initially hoped that its changing brightness might provide concrete observational evidence to support or modify the Copernican doctrine.
Digges's hopes were frustrated, as the star simply faded from view. But he nevertheless became the first English author publicly to declare his support for Copernicus's cosmological scheme, in the 1576 edition of his father's A Prognostication Everlasting. As an appendix to this popular almanac, Digges included his 'Perfit description of the caelestiall orbes', which made Copernicus's general claims accessible to an English audience by providing a free translation of the cosmological sections of book one of De revolutionibus orbium caelestium (1543). Digges also added his own touches, particularly in a famous diagram which went beyond Copernicus's own scheme, by showing an infinite universe in which the stars extended indefinitely outwards from the solar system.
In parallel with his innovative mathematical work of the early 1570s Digges also began a gentlemanly career of service. He was selected as MP for Wallingford in 1572 and sat at this parliament's subsequent sessions in 1576 and 1581. For the next parliament in 1584, he was returned as MP for Southampton. Over this period Digges was increasingly active, whether making speeches, sitting on committees, or consulting with the privy council. He has been identified as one of the House of Commons' 'men of business' and he earned a reputation for speaking 'for the common wealth of all England, and for no private cause' (Hitchcock, last page).
Digges's parliamentary work reached a peak in 1584-5 when he drafted memoranda on such topics as the provision of a standing army, the oath of association, a bill on Jesuits, and the question of the succession to Queen Elizabeth. He was by then a prominent and respected figure: 'Digges commonly doth speak last, and therefore saith, every matter must have an end, and therefore to draw this to a conclusion' (HoP, Commons, 38). Outside parliament he took on other public duties. He promoted plans for a new harbour at Dover in the early 1580s and involved himself in the detailed design of this major Elizabethan technical project. He was appointed a commissioner for the harbour in 1582 and made surveyor, but delegated his responsibilities to a local deputy. His mathematical skills were also called on in 1582 when he was asked to review John Dee's proposal for reform of the calendar, prepared after the introduction of the Gregorian calendar.
Rather than keep them in separate spheres, Digges sought to integrate his twin commitments to civic service and to mathematics. As early as 1576 he had included a programmatic call for the mathematical reformation of navigation along with the Copernican appendix to his father's Prognostication Everlasting. He subsequently spent fifteen weeks at sea, both to satisfy himself and to overcome the scepticism of experienced mariners. Digges not only proclaimed his criticisms of navigational errors to be triumphantly vindicated, but demonstrated that he could not be dismissed as merely a study-bound scholar.
Digges developed his vision of the identity of the mathematician most explicitly in Stratioticos (1579), a text on military mathematics. He confessed that he had once been delighted with the elevated subtlety of mathematical demonstration but that, with more mature judgement, he had spent his time 'in reducing the Sciences Mathematical from Demonstrative Contemplations to Experimental Actions, for the Service of my Prince and Country' (Stratioticos, 1579, sig. A2r). Stratioticos exemplifies this self-conscious choice of role and agenda. Its first book is on arithmetic and was based on surviving manuscript material of Leonard Digges. The remaining two books are Thomas Digges's own, adapting elementary algebra for use by soldiers and providing a lengthy treatment of the qualities and roles of all the ranks of men in an army. The volume was dedicated to the earl of Leicester, and had been composed in response to hopes over the winter of 1577-8 that he would lead an English force against the Spanish in the Netherlands. The last book of Stratioticos was evidently intended as a blueprint for a model army and, although Leicester's expedition came to nothing at the time, Digges himself visited the Low Countries in the autumn of 1578, touring and reporting on fortifications, and observing the troops.
When the Netherlands crisis came to a head in the mid-1580s Digges was again exhorting Leicester to active intervention. He was appointed as both trench-master and muster-master in the expeditionary force sent over in late 1585 and, after initially busying himself surveying fortifications, concentrated wholly on the office of muster-master. Although praised for his unswerving rectitude, his attempts to check abuses in the distribution of soldiers' pay led to increasing hostility and dispute. Far removed from the textbook military prescriptions of Stratioticos, Digges already complained of intolerable malice in September 1586 and, when he finally received his official discharge in early 1588, he considered that the disorders and abuses plaguing the army were above his power to remedy.
Digges's last years were dogged by continued and bitter wrangling over his army accounts and his position was weakened by the loss of his principal patron. While he appears to have been most closely linked with Lord Burghley in the early 1570s, by the end of the decade Digges had aligned himself with the activist and interventionist policy associated with Leicester. As well as the dedication of Stratioticos and the contacts leading to Digges's military service, Digges was nominated to his parliamentary seat in 1584 by Leicester; in addition, he named his eldest son Dudley after his patron. Digges also served Leicester in print, defending his reputation and military honour in both A Briefe Report of the Militarie Services done in the Low Countries, by the Erle of Leicester (1587) and A Briefe and True Report of the Proceedings of the Earle of Leycester for the Reliefe of the Towne of Sluce (1590).
Despite promising books on a wide range of mathematical subjects, Stratioticos was Digges's last major composition. His military concerns were reflected in new editions of Stratioticos (1590) and Pantometria (1591), which both contained additions on artillery, and particularly ballistics. Digges had built once again on prior work of his father by publishing a series of questions on artillery in the first edition of Stratioticos. His subsequent answers and notes of 1590 and 1591 foreshadowed his projected treatise on the subject and also demonstrated how advanced mathematics could be brought to bear on urgent military matters.
Despite the disappointments of his own military service, Digges still upheld the ideal of joining theory and practice in the service of the commonwealth. In presenting himself as a gentleman mathematician he became probably the most important Elizabethan promoter of mathematics as an engaged and effective worldly practice. His significance lay not only in his advocacy of novel geometry and cosmology but in shaping the tradition of practical mathematics.
Digges established his country residence at Chevening in Kent and also maintained a house in London. He married Anne (or Agnes), daughter of Sir Warham St Leger, and his will lists their surviving children as Dudley Digges (1582/3-1639), Margaret, Ursula, and Leonard Digges. Digges died on 24 August 1595 and his will was proved on 1 September, being opposed by his brother James and by William Digges, who were excluded by codicil. He was buried in the chancel of St Mary Aldermanbury, London, where his wife erected a monument to his memory.
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