SIR

See also:

• JAMES
• JAMES (Gr. 'IlrKw,l3or, the Heb. Ya`akob or Jacob)
• JAMES (JAMES FRANCIS EDWARD STUART) (1688-1766)
• JAMES, 2ND EARL OF DOUGLAS AND MAR(c. 1358–1388)
• JAMES, DAVID (1839-1893)
• JAMES, EPISTLE OF
• JAMES, GEORGE PAYNE RAINSFOP
• JAMES, HENRY (1843— )
• JAMES, JOHN ANGELL (1785-1859)
• JAMES, THOMAS (c. 1573–1629)
• JAMES, WILLIAM (1842–1910)
• JAMES, WILLIAM (d. 1827)

JAMES

See also:

• IVORY (Fr. ivoire, Lat. ebur)
• SIR JAMES IVORY (1765-1842)

IVORY (1765-1842)  , Scottish mathematician, was born in Dundee in 1765 . In 1779 he entered the university of St Andrews, distinguishing himself especially in mathematics . He then studied theology; but, after two sessions at St Andrews and one at Edinburgh, he abandoned all idea of the church, and in 1786 he became an assistant-teacher of mathematics and natural philosoghy in a newly established academy at Dundee . Three years later he became partner in and manager of a flax-spinning company at Douglastown in Forfarshire, still, however, prosecuting in moments of leisure his favourite studies . He was essentially a self-trained mathematician, and was not only deeply versed in ancient and modern geometry, but also had a full knowledge of the analytical methods and discoveries of the continental mathematicians . His earliest memoir, dealing with an analytical expression for the rectification of the ellipse, is published in the Transactions of the Royal Society of Edinburgh (1796); and this and his later papers on " Cubic Equations " (1799) and " Kepler's Problem " (1802) evince great facility in the handling of algebraic formulae . In 1804 after the dissolution of the flax-spinning company of which he was manager, he obtained one of the mathematical chairs in the Royal Military College at Marlow (afterwards removed to Sandhurst); and till the year 1816, when failing health obliged him to resign, he discharged his professional duties with remarkable success . During this period he published in the Philosophical Transactions several important memoirs, which earned for him the Copley medal in 1814 and ensured his election as a Fellow of the Royal Society in 1815 . Of special importance in the history of attractions is the first of these earlier memoirs (Phil . Trans., 1809), in which the problem of the attraction of a homogeneous ellipsoid upon an external point is reduced to the simpler case of the attraction of another but related ellipsoid upon a corresponding point interior to it . This theorem is known as Ivory's theorem . His later papers in the Philosophical Transactions treat of astronomical refractions, of planetary perturbations, of equilibrium of fluid masses, &c .

For his investigations in the first named of these he received a royal medal in 1826 and again in 1839 . In 1831, on the recommendation of

Lord Brougham, King William IV. granted him a pension of £300 per annum, and conferred on him the Hanoverian Guelphic order of knighthood . Besides being directly connected with the chief scientific societies of his own country, the Royal Society of Edinburgh, the Royal Irish Academy, &c., he was corresponding member of the Royal Academy of Sciences both of Paris and Berlin, and of the Royal Society of Gottingen . He died at London on the 21st of September 1842 . A list of his works is given in the Catalogue of Scientific Papers of the Royal Society of London .