James Ivory | |
|---|---|
| Born | (1765-02-17)17 February 1765 |
| Died | 21 September 1842(1842-09-21) (aged 77) |
| Alma mater | Dundee Academy[1] University of St Andrews[1] Edinburgh University[1] |
| Parents |
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| Awards | Copley Medal(1814) Royal Medal(1826, 1839) |
| Scientific career | |
| Fields | mathematics theology |
James Ivory,FRSFRSEKH LLD (17 February 1765 – 21 September 1842) was a Britishmathematician. He stated and provedIvory's lemma.
Ivory was born inDundee, son of watchmakerJames Ivory. The family lived and worked on the High Street in Dundee.[2]
He was educated atDundee Grammar School. In 1779 he entered theUniversity of St Andrews, distinguishing himself especially in mathematics. He then studiedtheology; but, after two sessions at St Andrews and one atEdinburgh University, he abandoned all idea of the church, and in 1786 he became an assistant-teacher of mathematics and natural philosophy in the newly establishedDundee Academy. Three years later he became partner in, and manager of, a flax spinning company at Douglastown inForfarshire, while continuing mathematical research as a hobby. He was essentially a self-trained mathematician, and was not only deeply versed ingeometry, but also kept up with contemporary developments inmathematical analysis.[3]
He published a memoir with ananalytical expression for the rectification of theellipse in theTransactions of the Royal Society of Edinburgh (1796), and two others oncubic equations (1799) and theKepler problem (1802). In 1804 the flax-spinning company he managed was dissolved, and he obtained one of the mathematical chairs in theRoyal Military College, Great Marlow (later moved to Sandhurst), at which he remained until 1816, when failing health obliged him to resign.[3]
During this period he published several important memoirs in thePhilosophical Transactions, which earned for him theCopley Medal in 1814 and ensured his election as aFellow of the Royal Society in 1815. Of special importance in the history of attractions is the first of these (1809), in which the attraction of a homogeneous ellipsoid upon an external point is reduced to the simpler case of the attraction of a related ellipsoid upon a corresponding point interior to it. This theorem is known as Ivory's theorem,[3] though one of itslemmas,Ivory's lemma, is better known today and is itself sometimes called Ivory's theorem. He also anonymously published an edition ofEuclid'sElements, which was described as having brought the difficult problems "more within the reach of ordinary understandings".[4] His later papers in thePhilosophical Transactions discuss astronomical refractions, planetary perturbations, equilibrium of fluid masses, etc. For his astronomical investigations he received a royal medal in 1826 and again in 1839.[3]
In 1831, on the recommendation of Lord Brougham,King William IV granted him a yearly pension of £300 and appointed him Knight of theRoyal Guelphic Order.[3] He was directly connected with the Royal Society of Edinburgh and the Royal Irish Academy, and was corresponding member of the Royal Academies of Sciences ofParis andBerlin, and of the Royal Society ofGöttingen.[3]
In 1839, the University of St. Andrews conferred on him an honorary degree as a Doctor of Laws (LLD).[5]
He died inHampstead in north London on 21 September 1842.[6]
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