Moore, Sir Jonas

(1617-1679), mathematician and patron of astronomy

by Frances Willmoth

© Oxford University Press 2004 All rights reserved

Moore, Sir Jonas (1617-1679), mathematician and patron of astronomy, was born on 8 February 1617 at White Lee (now Higher Whitelee Farm) near the village of Higham in Pendle Forest, Lancashire, the second (or second surviving) son of Hugh Moore (d. 1649) and his wife, Mary Aspinall (d. 1623). Both the Moore and Aspinall families included some minor gentry, but Hugh Moore seems to have had the status of a prosperous yeoman. Three years after Mary Moore died Hugh married Frances (née Whitaker), the widow of William Starkie, second son of Edmund Starkie of Huntroyd.

It is probable that Moore went to a local grammar school. He appears not to have attended a university, but furthered his education by reading mathematical books, assisted and encouraged by friends, especially members of the Presbyterian (and later parliamentarian) Shuttleworth family of nearby Gawthorpe Hall. He later said that the inventor William Gascoigne, of Middleton, near Leeds, had given him 'good information in mathematicall knowledge' (Brief Lives, 2.80), and that he had used the library of the antiquarian Christopher Towneley of Carr Hall, but there is no evidence that he was in contact with them, or with other members of the Towneley family, before the 1640s.

On 24 November 1637 Moore was appointed clerk to Thomas Burwell, who, as spiritual chancellor and vicar-general, presided over the ecclesiastical courts of the diocese of Durham. The post proved short-lived, as the courts ceased to function when the region was invaded by the Scots in August 1640, and formally ceased to exist in October 1642. A signature on the Durham Protestation of February 1642 shows that Moore was then still in the city, but he probably left before the end of that year. His whereabouts during the civil war period are unknown, though it appears that he initially sent his family back to Lancashire. On 8 April 1638 at St Giles, Durham, Moore married Helenora (probably Eleanor, baptized on 2 October 1604), the daughter of Ralph Wren of Durham, a relation of the wealthy and locally influential Wrens of Binchester. The Moores' elder daughter, Mary, was baptized at St Mary-le-Bow, Durham, on 24 March 1639, and the younger, Helen or Ellen, at Padiham, Lancashire, on 1 January 1641. A son, Jonas, was the youngest of the three children; the date and place of his birth and baptism are unknown, as are the date and place of Eleanor's death and burial, though there is evidence that she predeceased her husband.

During the time of the Scots invasion Moore furthered his mathematical studies by visiting William Milburne at Brancepeth. He then found the subject a useful resource when he needed a livelihood, and established himself as a teacher with the aid of the figurehead of English mathematics, William Oughtred, settling in London by the late 1640s. In the 1647 Key of the Mathematics, the first English edition of Oughtred's famous Clavis, an authorial preface pays glowing tribute to Moore and Thomas Wharton for the 'exceeding great paines and expense', they had bestowed in correcting and proof-reading the volume. In the same year, when the royal children were in the custody of parliament, Moore briefly held the post of tutor in 'Arithmetick, uses of the Globes, and Geography' to James, duke of York; the several dedications to his 1650 Arithmetick show that he had other well-connected pupils. Its preface was dated from the house of Elias Allen, a leading instrument maker and close friend of Oughtred.

Moore later attributed his rise in the world to his work as surveyor to the fifth earl of Bedford's fen drainage company. He was first mentioned in the company's minutes, and perhaps briefly employed, in June 1649; on 26 August 1650 his appointment as surveyor from 2 September following was confirmed. He went on to serve for four years at £200 per annum and for at least one more at £100. He was probably peripatetic at first, but in February 1652 brought his family to live in the fens, at March, Cambridgeshire; in 1653 they moved to Southery, on the fenland edge of Norfolk. The surveyor's duties were 'to sett out the works and see that they bee done' (Bedford Level Corporation records, R, fol. 31r), to measure land for compensation and completed work so that it could be paid for, to help resolve legal disputes, and to convince the commissioners appointed to judge the project's success.

Moore was thus much more closely involved in day-to-day management of the work than was the nominal director, Sir Cornelius Vermuyden; recent research has indicated that he and not Vermuyden was responsible for commissioning the massive sluice at Denver in 1655. He also eventually produced the general map that the company had requested from the start. A single-sheet version (c.1654) appeared in a variant form in William Dugdale's History of Embanking and Drayning (1662), and provided the basis for a two-sheet map (1685). In late 1657 or early 1658 Moore published a huge sixteen-sheet Mapp of the Great Levell of the fens, displaying the coats of arms of Cromwellian drainage investors (the sole known copy is in the Public Record Office: MPC 88). This map's large scale and claims to mathematical accuracy earn it a unique place in English cartographical history. A new edition lacking arms was issued by Moses Pitt (1684) and later reprinted (c.1706).

Moore marked his return to London by publishing Resolutio Triplex (1658), an answer to a French geometrical challenge, followed by a pamphlet, Short Introduction into the Art of Species [algebra] (1660), and a revised edition of his Arithmetick (1660). As this last appeared after the Restoration, Moore used it to claim royalist credentials (not altogether convincingly); the duke of York was the principal dedicatee. The author's address was advertised as in Stanhope Street, on the fashionable western side of London; he went on to occupy a succession of nearby houses in Blackamore Street, Drury Lane, and Kings Head Court. For the next few years he derived his income from teaching and from a variety of short-term projects, such as surveying the manor of Woburn (1661) and mapping the Thames for the Navy Board (1662). In 1663 he joined an expedition to the new English possession of Tangier to help plan a fortified harbour wall, known as 'the Mole'; on his Mapp of the Citty of Tanger [1664] he is termed surveyor to the duke of York.

On 19 June 1665, during the Second Dutch War (1665-7), Moore was appointed temporary assistant surveyor of the royal ordnance. He succeeded to the permanent post of surveyor general on 28 July 1669 and held it until his death ten years later. The surveyor was one of the principal officers of the Board of Ordnance, with particular responsibility for incoming stores and fortifications, duties which were burdensome only in wartime; Moore undertook them himself rather than appointing a deputy. From 1665 he lived near the Tower of London and from 1669 in an official house in its grounds. The Third Dutch War (1672-4) placed heavy demands upon the office; meeting them helped earn Moore his knighthood, conferred on 28 January 1673, and the reversion of the surveyorship for his son.

During the war Moore published Modern Fortification (1673). A General Treatise of Artillery (1673), translated from the Italian, is sometimes attributed to him but was in fact produced by his son. Then he reverted to more general mathematical concerns: his notes were edited by his Ordnance second clerk, Nicholas Stephenson, to form a pocket-book, Mathematical Compendium (1674). Stephenson was also deputed by Moore to compile the Royal Almanack (annually, 1674-8), a strictly non-astrological almanac containing astronomical tables by John Flamsteed, tide-tables, and other practical information.

Moore first met Flamsteed in 1670, through their mutual acquaintance John Collins. They corresponded occasionally after Flamsteed's return to Derby, and from March 1674 more frequently, with Moore offering 'to assist yow with eyther Bookes or Instrumentes' (Royal Greenwich Observatory archives, RGO 1/37, fol. 73r) and financially; most of these letters survive among Flamsteed's papers. By the autumn of 1674 Moore was planning to provide Flamsteed with a permanent income, perhaps by 'moveing his Majesty for a yearly Annuity' (ibid., fol. 78r). In the meantime he considered establishing an observatory at Chelsea College, which belonged to the Royal Society; this proved impractical, but the society's interest in the project led to Moore's election as a fellow on 3 December 1674. In February 1675 a committee appointed by the king to assess a proposed astronomical means of finding longitude at sea co-opted Flamsteed as an adviser; its members accepted his claims about the inadequacy of all existing data, and, in Flamsteed's words, 'readily joined with Sir Jonas Moore to move the King that an Observatory might be built ... and myself to be employed in it ... which his Majesty was graciously pleased to grant' (Baily, 125-6). The warrant was signed on 4 March 1675, and the building of an observatory at Greenwich was authorized in the following June.

The leading role Moore played in the foundation, constructing, and equipping of the observatory was acknowledged in an inscription placed near its door, and in a plate accompanying views of the park, buildings, and instruments, commissioned by Moore from the draughtsman Robert Thacker and engraver Francis Place (c.1676). The observatory's key instruments--a large sextant, a 7 foot mural quadrant designed by Robert Hooke, and two sophisticated clocks by Thomas Tompion--were paid for by Moore personally, at a cost of several hundred pounds. In return he exercised considerable influence over the institution's work, and continued to intervene in its affairs until his death; his attempts to make Flamsteed publish results caused much friction between them.

During the same period Moore was also involved with the management of the Royal Mathematical School at Christ's Hospital, having been made a governor of the hospital in December 1676. He began to compile a textbook for the school's use, writing parts himself and incorporating contributions by Flamsteed, Halley (another of his protégés), and the school's master, Peter Perkins. Moore's sons-in-law, William Hanway and John Pottenger, saw the work completed and posthumously published, in lavish style, as A New Systeme of the Mathematicks (2 vols., 1681).

Moore's death was described by an Ordnance colleague's wife as follows:

Joaney Moore had but three fitts of a fever, and the fourth carried him away; he died ... coming from that rotten place Portsmouth, whither he was very unwilling to goe, but nothing would satisfy the imperious Governor but he must come. (Lady Newton, 80)
He died at Godalming, Surrey, during the night of 26-7 August 1679; on 2 September his body was buried in the Tower chapel of St Peter ad Vincula, where a monument was later set up by his elder daughter. Since he had made no will, a legal battle between his son and daughters followed; two extensive probate inventories of his goods and funeral expenses survive (PRO PROB 4/18757 and 5/4229). Jonas Moore junior succeeded to the surveyorship but died in 1682; his father's outstanding mathematical library was sold at auction in 1684. An anonymous verse eulogy To the Memory of my most Honoured Friend Sir Jonas Moore was published soon after the elder Moore's death. Another tribute came from his friend John Aubrey, whose brief life terms him 'a good mathematician and a good fellow'. Aubrey noted details not recorded elsewhere, and described his appearance later in life as 'tall and very fat, [with] thin skin, faire, clear grey eie'.


F. H. Willmoth, Sir Jonas Moore: practical mathematics and Restoration science (1993) [incl. bibliography]
F. Baily, An account of the Revd John Flamsteed, the first astronomer-royal (1835); repr. (1966)
The correspondence of John Flamsteed, the first astronomer royal, ed. E. G. Forbes and others, 1 (1995)
The preface to John Flamsteed's Historia coelestis Britannica, or, British catalogue of the heavens, ed. A. Chapman, trans. A. D. Johnson (1982)
The diary of Robert Hooke ... 1672-1680, ed. H. W. Robinson and W. Adams (1935)
Brief lives, chiefly of contemporaries, set down by John Aubrey, between the years 1669 and 1696, ed. A. Clark, 2 (1898), 79-81
Lady Newton, Lyme letters (1925), 80
Cambs. AS, Cambridge, Bedford Level Corporation records, R 59.31
CUL, Royal Greenwich Observatory papers, RGO 1/36; 1/37

Cambs. AS, Bedford Level corporation records
CUL, Royal Greenwich Observatory archives, Flamsteed MSS

T. Cross, line engraving (after H. Stone), BM, NPG, V&A; repro. in J. Moore, Moore's arithmetick (1650), frontispiece [see illus.]
line engraving, BM; repro. in J. Moore, Moor's arithmetick (1660), frontispiece

Wealth at death  
over £4750--incl. revenue from sale of library: inventories, PRO, PROB 4/18757; PRO, PROB 5/4229

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