Samuel Hunter Christie
Encyclopedia
Samuel Hunter Christie was a British scientist
and mathematician
.
He studied mathematics
at Trinity College, Cambridge
where he was second wrangler. 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, delivered their Bakerian Lecture
in 1833 and served as their Secretary from 1837 to 1853. In 1833 he published his 'diamond' method, the forerunner of the Wheatstone bridge
, in a paper on the magnetic and electrical properties of metal
s, as a method for comparing the resistances of wire
s of different thicknesses. However, the method went unrecognised until 1843, when Charles Wheatstone
proposed it, in another paper 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).
Samuel Christie is the son of one James Christie, although this was almost certainly not the auctioneer James Christie (founder of the great auction house). Instead he was probably the son of a 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. Because of they had the same name, some confusion has arisen between the two James Christie's and many websites incorrectly state that he was the son of 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.
Scientist
A scientist in a broad sense is one engaging in a systematic activity to acquire knowledge. In a more restricted sense, a scientist is an individual who uses the scientific method. The person may be an expert in one or more areas of science. This article focuses on the more restricted use of the word...
and mathematician
Mathematician
A mathematician is a person whose primary area of study is the field of mathematics. Mathematicians are concerned with quantity, structure, space, and change....
.
He studied mathematics
Mathematics
Mathematics is the study of quantity, space, structure, and change. Mathematicians seek out patterns and formulate new conjectures. Mathematicians resolve the truth or falsity of conjectures by mathematical proofs, which are arguments sufficient to convince other mathematicians of their validity...
at Trinity College, Cambridge
Trinity College, Cambridge
Trinity College is a constituent college of the University of Cambridge. Trinity has more members than any other college in Cambridge or Oxford, with around 700 undergraduates, 430 graduates, and over 170 Fellows...
where he was second wrangler. He was particularly interested in magnetism
Magnetism
Magnetism is a property of materials that respond at an atomic or subatomic level to an applied magnetic field. Ferromagnetism is the strongest and most familiar type of magnetism. It is responsible for the behavior of permanent magnets, which produce their own persistent magnetic fields, as well...
, studying the earth's magnetic field
Earth's magnetic field
Earth's magnetic field is the magnetic field that extends from the Earth's inner core to where it meets the solar wind, a stream of energetic particles emanating from the Sun...
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, delivered their Bakerian Lecture
Bakerian Lecture
The Bakerian Lecture is a prize lecture of the Royal Society, a lecture on physical sciences.In 1775 Henry Baker left £100 for a spoken lecture by a Fellow on such part of natural history or experimental philosophy as the Society shall determine....
in 1833 and served as their Secretary from 1837 to 1853. In 1833 he published his 'diamond' method, the forerunner of the Wheatstone bridge
Wheatstone bridge
A Wheatstone bridge is an electrical circuit used to measure an unknown electrical resistance by balancing two legs of a bridge circuit, one leg of which includes the unknown component. Its operation is similar to the original potentiometer. It was invented by Samuel Hunter Christie in 1833 and...
, in a paper on the magnetic and electrical properties of metal
Metal
A metal , is an element, compound, or alloy that is a good conductor of both electricity and heat. Metals are usually malleable and shiny, that is they reflect most of incident light...
s, as a method for comparing the resistances of wire
Wire
A wire is a single, usually cylindrical, flexible strand or rod of metal. Wires are used to bear mechanical loads and to carry electricity and telecommunications signals. Wire is commonly formed by drawing the metal through a hole in a die or draw plate. Standard sizes are determined by various...
s of different thicknesses. However, the method went unrecognised until 1843, when Charles Wheatstone
Charles Wheatstone
Sir Charles Wheatstone FRS , was an English scientist and inventor of many scientific breakthroughs of the Victorian era, including the English concertina, the stereoscope , and the Playfair cipher...
proposed it, in another paper 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).
Samuel Christie is the son of one James Christie, although this was almost certainly not the auctioneer James Christie (founder of the great auction house). Instead he was probably the son of a 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. Because of they had the same name, some confusion has arisen between the two James Christie's and many websites incorrectly state that he was the son of 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: Posting on RootsWeb)
- Margaret Ellen (married c.1844; source: Woolwich churchyard inscription)