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JONES , WILLIAM ( 1675? - 1749 ; DWB , 522-3).

In the bibliography read History of the Island of Mona or Anglesey (not ‘ Isle of Anglesey ’).

He was born in 1674 or 1675 ; the same year as the father of the Morris brothers of Anglesey (see Lewis Morris , DWB , 661 , Richard Morris , DWB , 663-4 , William Morris , DWB , 666-7 ). He d. 1 July , not 3 July , 1749 , and was buried in St. Paul's church , Covent Garden on 7 July 1749 . He was married twice: (1) to the widow of the merchant who employed him when he went to London . This might explain how he came by the money which he later lost; and (2) to Mary Nix on 17 Apr. 1731 when he was 56 and she was 25.

He left his mark on mathematics in several ways. The use of the symbol π to designate the ratio of the circumference of a circle to its diameter first appeared in his book Synopsis Palmarorium Matheseos ( 1706 ) and it was he, in his editions of Newton 's works who used the dot as the differential sign in the calculus . In one of his papers in the Trans. of the Royal Society he created a rule for compound interest and many mathematicians of the period sought his opinion of their work.

In his will he left his library of some 15,000 works and over 50,000 pages of manuscripts, including hundreds of pages refering to those whom he knew and several of Newton 's MSS. to the 3rd Earl Macclesfield , most of which remain in the earl 's home, Shirburn Castle .


  • Hugh Owen (ed.), Additional Letters of the Morrises of Anglesey (1735-86). Y Cymmrodor , xlix, 1947-9 (1753-86) , Y Cymmrodor , 49 (1947-49) , 253;
  • The General Advertiser , London, 1743-1752 , 3 July 1749 (4585);
  • Register of St. Paul's church, Covent Garden;
  • Register of St. Lawrence Jewry and St. Mary Magdalen, Milk Street;
  • D. T. Whiteside (ed.), The Mathematical papers of Sir Isaac Newton , Cambridge, 1967 (1967) , 400;
  • S. J. Rigaud (ed.), Correspondence of Scientific Men of the Seventeenth Century, including letters of Barrow, Flamsteed, Wallis, and Newton, printed from the originals in the collection of the Right Hon. the Earl of Macclesfield , Oxford, 1841 (1841) , 256;
  • letters from D. T. Whiteside , Un. of Wales Bangor 2659A;
  • Charles Hutton , Mathematical Tables containing common, hyperbolic, and logistic logarithms. Also sines, tangents, secants, and versed-sines , London, 1785 (1785), 117.


Dr Llewelyn Gwyn Chambers, Bangor

Corrections and additions:

JONES , WILLIAM ( 1675? - 1749 ), mathematician ;

b. at Merddyn , Llanfihangel Tre'r Beirdd , Anglesey (the next farm to the birthplace of Lewis , Richard , and William Morris ); the family removed to Tyddyn-bach , Llanbabo , and when the father d. the mother went to live at Clymwr in the same parish — hence the Morrises ’ nickname, ‘ Pabo ,’ for William Jones . The father was John George ; the mother was Elizabeth Rowland , of the family of Bodwigan , Llanddeusant ( J. E. Griffith , Pedigrees , 3), and Elizabeth 's mother was of the family of Tregaian and therefore, according to Lewis Morris ( Add. M.L. , p. 190), related to the Morrises ’ father and mother. His son's biography says that William Jones was b. in 1680 , but the D.N.B .'s ‘ 1675 ’ is more likely. He was at school at Llanfechell , and showed such skill as a calculator that his landlord ( Bulkeley of Baron Hill ) sent him up to London ; after a period in a countinghouse there he became instructor on a man-of-war , and attracted the notice of admiral Anson . Tutorships in great families followed; two of his pupils, Thomas Parker ( earl of Macclesfield ) and Philip Yorke ( earl Hardwicke ) became Lords Chancellor . Macclesfield afterwards took him as tutor to his son, and Shirburn castle became Jones 's home for many years. He lost heavily when his banker failed, but his friendship with the great brought him profitable sinecures. He m. Mary Nix ; they had two sons and a daughter. He d. in London , 3 July 1749 . His mathematical works (on which see D.N.B. ) were very highly esteemed; he was a friend of Halley 's and of Newton 's (some of whose works he edited), was F.R.S. in 1712 , and became vice-president of the Society .

It will be seen that Jones 's career fell outside Wales , and his contacts with Welsh concerns were casual, though none the less interesting. It seems that Richard alone of the Morrises knew him personally, though Lewis in 1749 (see above) wrote to him. But in 1747 ( Morris Letters , 129), we find Richard suggesting that Jones should propose Lewis for membership of the Royal Society — a service which he had already rendered to Moses Williams ( 1685 - 1742 ) . When Richard Morris 's edition of the Welsh Bible appeared ( 1746 ), it included two maps, ‘a gift of William Jones , F.R.S. , to the Welsh people.’ On the death of Moses Williams , his widow sold his books and manuscripts to his friend William Jones , and Richard Morris took on the cataloguing of the manuscripts . But when Jones in his turn d., the manuscripts went, under his will, to his pupil the 2nd earl Macclesfield , who refused Morris further access to them. The earl talked of giving them to the British Museum , but in fact they remained at Shirburn for some 150 years — Angharad Llwyd tells us that she too offered to complete the catalogue but was told that the manuscripts ‘ were not worth the trouble .’ But in 1899 they were bought by Sir John Williams and catalogued by J. Gwenogvryn Evans — they are today (with Richard Morris 's notes and indexes) in the National Library of Wales .

William Jones 's youngest child, Sir WILLIAM JONES ( 1746 - 1794 ), gained very great fame as a philologist and an authority on Hindu law ; there is a biography ( Memoirs of Sir W. Jones , 1804 ) by lord Teignmouth , and a full article in D.N.B. He was b. 28 Sept. 1746 , m. Anna , sister of dean W. D. Shipley , and d. 27 April 1794 at Calcutta . He spoke no Welsh , and though he had a slight reading knowledge of it he never studied it systematically — a witty British ambassador in Paris presented him to the French king as ‘ a man who knew every language except his own .’ He was a member of the Cymmrodorion in 1778 , and a letter written by Richard Morris junior from India in 1785 ( Add. M.L. , p. 781) reveals that he was discussing with William Jones the project of publishing Lewis Morris 's Celtic Remains ; but Angharad Llwyd quotes from a letter of his ( 1790 ) to Morris , which avers that ‘though, as a Cymmrodor , he was keenly interested in the antiquities and literature of Wales , yet he had not a minute to spare for them.’


  • Oxford Dictionary of National Biography (on both men);
  • Memoirs of the life, writings and correspondence, of Sir William Jones , London, 1804 ;
  • Y Cymmrodor , viii;
  • Angharad Llwyd , A History of the Island of Mona, or Anglesey including an account of its natural productions, Druidical antiquities, lives of eminent men, the customs of the court of the ancient welsh princes, etc. :being the prize essay to which was adjudged the first premium at the Royal Beaumaris Eisteddfod, held in the month of August, 1832 , Rhuthin, 1833 , 381;
  • Richard Parry (Gwalchmai) , Enwogion Môn , 1877 ;
  • Y Cymmrodor , 1951 , 45;
  • and other sources mentioned above.


Emeritus Professor Robert Thomas Jenkins, C.B.E., D.Litt., Ll.D., F.S.A., (1881-1969), Bangor

Published date: 2001