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# Peter Barlow

Peter Barlow (13 October 1776 – 1 March 1862)[1][2] was an English mathematician and physicist.

Work in mathematics

In 1801, Barlow was appointed assistant mathematics master at the Royal Military Academy, Woolwich,[1][3] and retained this post until 1847.[2] He contributed articles on mathematics to The Ladies' Diary[3] as well as publishing books such as:[1][3]

An Elementary Investigation of the Theory of Numbers (1811);

A New Mathematical and Philosophical Dictionary (1814); and

New Mathematical Tables (1814).

The latter became known as Barlow's Tables and gives squares, cubes, square roots, cube roots, and reciprocals of all integer numbers from 1 to 10,000. These tables were regularly reprinted until 1965,[2] when computers rendered them obsolete. He contributed to Rees's Cyclopaedia articles on Algebra, Analysis, Geometry and Strength of Materials. Barlow also contributed largely to the Encyclopaedia Metropolitana.

Peter Barlow

Work in physics and engineering

Barlow made an important contribution to astronomy by inventing, in collaboration with optician George Dollond, the Barlow lens, an achromatic telescope lens in which two glass layers enclosed a colourless liquid (later replaced by a different kind of glass).[1][3] In 1823 he was made a fellow of the Royal Society and two years later received its Copley Medal for his work on correcting the deviation in ship compasses caused by the presence of iron in the hull.[1][3] Some of his magnetic research was done in collaboration with Samuel Hunter Christie. Barlow's wheel is an early electric motor he invented, while Barlow's law is an (incorrect) law describing electrical conductance.

Steam locomotion received much attention at Barlow's hands and he sat on the railway commissions of 1836, 1839, 1842 and 1845. He also conducted several investigations for the newly-formed Railway Inspectorate in the early 1840s.

Barlow made several contributions to the theory of strength of materials, including Essay on the strength and stress of timber (1817) which contains experimental data collected at Woolwich. The sixth edition (1867) of this work was prepared by Barlow's two sons after his death and contains a biography of their father. Barlow also applied his knowledge of materials to the design of bridges.[3] His sons Peter W. Barlow and William Henry Barlow became notable civil engineers of the 19th century. He was elected a Foreign Honorary Member of the American Academy of Arts and Sciences in 1832.[4]

See also

2147483647, a Mersenne prime that Barlow commented on

References

Wikisource has the text of the 1911 Encyclopædia Britannica article Barlow, Peter.

^ a b c d e Encyclopædia Britannica Online: Peter Barlow

^ a b c Lance Day and Ian McNeil, Biographical dictionary of the history of technology, Routledge, 1995, page 42.

^ a b c d e f MacTutor Biography: Peter Barlow

^ "Book of Members, 1780-2010: Chapter B". American Academy of Arts and Sciences. Retrieved 17 May 2011.

External links

Barlow's Formula Calculator

Biographical information

Retrieved from "http://en.wikipedia.org/"

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