Sir Jonas Moore, FRS (1617–1679) was an English mathematician, surveyor, ordnance officer, and patron of astronomy. He took part in two of the most ambitious English civil engineering projects of the 17th century: draining the Great Level of the Fens and building the Mole at Tangier. In later life, his wealth and influence as Surveyor-General of the Ordnance enabled him to become a patron and driving force behind the establishment of the Royal Observatory, Greenwich.

Origins and early career

Jonas Moore was born at Higher White Lee, in Higham, which is in Pendle, Lancashire on 8 February 1617, a son of a yeoman farmer, John Moore. His older brother, also John, had allegedly been bewitched to death in about 1610 by Elizabeth Sothernes (Old Demdike), the most notorious of the Pendle witches. There is no record of Jonas's education but it is likely that he attended Burnley Grammar School, which was only three miles from his home. In 1637, he was appointed clerk to Thomas Burwell, Vicar-General of the diocese of Durham, a job requiring competence in the use of legal Latin. He married Eleanor Wren on 8 April 1638 in Durham, and subsequently raised a family of a son and two daughters. During the English Civil War, Parliament sequestered church revenues in October 1642, and Moore with no income had to return to Lancashire.

Jonas Moore

Mathematician and surveyor

Records of Moore's life during the next ten years are sketchy, but by 1650 he was an established mathematics teacher and published his first book, Moores Arithmetick. In 1674, Sir Jonas Moore first used the abbreviated notation 'cos' for the trigonometric term cosine. He went on that year to be appointed Surveyor to the Fen drainage Company of William Russell, 5th Earl of Bedford, and worked on draining the Fens for the next seven years. In 1658, Moore was able to produce a 16-sheet Mapp of the Great Levell of the Fens, which provided an effective means of displaying the Company's achievements in altering the Fenland landscape of East Anglia. The scale of the map (about two inches to the mile) was not to be bettered until the late 19th century.

Jonas Moore

In the early 1660s, Moore worked mainly as a surveyor, mapping the River Thames from "Westminster to the sea" in 1662, his first commission from a government body. From 1663, James, Duke of York became Moore's chief patron. In June, Moore visited Tangier (an English possession from 1661 to 1684) as part of a team to design a stone pier. On his return, he prepared a map with the title A Mapp of the Citty of Tanger with Straits of Gibraltar. Described by Jonas Moore Surveyor to his Royall Highness the Duke of York. When it was completed in March 1664, Samuel Pepys, an active member of the Tangiers Committee, was impressed with the map "which is very pleasant, and I purpose to have it finely set out and hung up."

Jonas Moore

Ordnance officer

With the patronage of the King's brother, Moore found a place as a member of the Ordnance Office. He was appointed Assistant Surveyor of the Ordnance on 19 June 1665 as full deputy to Francis Nicholls, who had been Surveyor since 1660. Moore became Surveyor-General of the Ordnance after the death of Nicholls on 28 July 1669.

The Surveyor's duties were not confined to land surveying; rather the main duty was to ensure availability of adequate stores, particularly guns and ammunition. During the Third Anglo-Dutch War, Moore met Prince Rupert at the Nore with 16 vessels loaded with powder and shot. He received his knighthood on 28 January 1673, probably as a reward for his duties during the first year of the Third Dutch War. With the end of the war in 1674, Moore was able to pursue his interest in astronomy and attempted to gain support from the Royal Society for an observatory at Chelsea College. Moore was elected to the Royal Society on 3 December 1674, but the proposal for an observatory at Chelsea came to nothing. He continued as an active member, and in May 1676 he was appointed a Vice-President of the Royal Society.

When Charles II appointed John Flamsteed his "astronomical observator" on 4 March 1675, Flamsteed had already enjoyed Moore's patronage since 1670, when Moore presented him with a Towneley micrometer. The Ordnance Office was responsible for the building of the Royal Observatory at Greenwich, which was completed in June 1676. Moore provided much of the Observatory's foundation equipment including the two "Great Clocks" by Thomas Tompion, out of his own pocket.