Samuel Hunter Christie

Samuel Hunter Christie (22 March 1784-24 January 1865) was a British scientist and mathematician. He studied mathematics at Trinity College, Cambridge. He was particularly interested in magnetism, studying the earth's magnetic field and designing improvements to the magnetic compass. Some of his magnetic research was done in collaboration with Peter Barlow. He became a fellow of the Royal Society in 1826, and served as its Secretary from 1837 to 1853. In 1833 he published his 'diamond' method, the forerunner of the Wheatstone bridge, in a paper¹ on the magnetic and electrical properties of metals, as a method for comparing the resistances of wires of different thicknesses. However, the method went unrecognised until 1843, when Charles Wheatstone proposed it, in another paper² for the Royal Society, for measuring resistance in electrical circuits. Although Wheatstone presented it as Christie's invention, it is his name, rather than Christie's, that is now associated with the device.

Christie taught mathematics at the Royal Military Academy, Woolwich from 1838 until his retirement in 1854. A portrait photograph of Christie in 1865 by Ernest Edwards is held by the National Portrait Gallery. He had ten children (five with each wife), of which eight survived him. His eldest son was the astronomer William Henry Mahoney Christie (1845-1922).

He was a Fellow of Royal Society.

Samuel Christie is the son of James Christie, 1776–1814. This was probably the James Christie who in 1821 described himself as a tailor, late of Leicester Square but then of Newman Street, and who died in 1825 aged eighty-six. Some confusion has apparently arisen between him and James Christie, the auctioneer. But, as the latter occupied a house in Pall Mall from 1768 until 1803, and died in that year, it seems certain that the James Christie who lived in Leicester Square was not the auctioneer.

Marriages

#Elizabeth Theadora (died c.1844; source: [http://archiver.rootsweb.com/th/index/LONDON/2000-04 Posting on RootsWeb] )
#Margaret Ellen (married c.1844; source: [http://www.kentarchaeology.org.uk/Research/Libr/MIs/MIsWoolwich/MIsWoolwich451-903.htm Woolwich churchyard inscription] )

References

# S. Hunter Christie, "The Bakerian Lecture: Experimental Determination of the Laws of Magneto-electric Induction in different masses of the same metal, and its intensity in different metals.", Philosophical Transactions of the Royal Society of London, vol. 123, 1833, pp. 95-142.
# Charles Wheatstone, "The Bakerian Lecture: An Account of Several New Instruments and Processes for Determining the Constants of a Voltaic Circuit", Philosophical Transactions of the Royal Society of London, vol. 133, 1843, pp. 303--327.
#'Leicester Square, West Side: Leicester Estate: Nos 43-54 Leicester Square', Survey of London: volumes 33 and 34: St Anne Soho (1966), pp. 507-514. [http://www.british-history.ac.uk/report.aspx?compid=41127.]