# 1911 Encyclopædia Britannica/Peacock, George

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​PEACOCK, GEORGE (1791–1858), English mathematician, was born at Thornton Hall, Denton, near Darlington, on the 9th of April 1791. He was educated at Richmond, Yorkshire, and entered Trinity College, Cambridge, in 1809. He was second Wrangler in 1812 (Sir J. F. W. Herschel being senior), was elected fellow of his college in 1814, became assistant tutor in 1815 and full tutor in 1823. While still an undergraduate he formed a league with John Herschel and Charles Babbage, to conduct the famous struggle of “d-ism versus dot-age,” which ended in the introduction into Cambridge of the continental notation in the infinitesimal calculus to the exclusion of the fluxional notation of Sir Isaac Newton. This was an important reform, not so much on account of the mere change of notation (for mathematicians follow J. L. Lagrange in using both these notations), but because it signified the opening to the mathematicians of Cambridge of the vast storehouse of continental discoveries. The analytical society thus formed in 1813 published various memoirs, and translated S. F. Lacroix’s Differential Calculus in 1816. Peacock powerfully aided the movement by publishing in 1820 A Collection of Examples of the Application of the Differential and Integral Calculus. In 1841 he published a pamphlet on the ​university statutes, in which he indicated the necessity for reform; and in 1850 and 1855 he was a member of the commission of inquiry relative to the university of Cambridge. In 1837 he was appointed Lowndean professor of astronomy. In 1839 he took the degree of D.D., and the same year was appointed by Lord Melbourne to the deanery of Ely. Peacock threw himself with characteristic ardour into the duties of this new position. He improved the sanitation of Ely, published in 1840 Observations on Plans for Cathedral Reform, and carried out extensive works of restoration in his own cathedral. He was twice prolocutor of the lower house of convocation for the province of Canterbury. He was also a prime mover in the establishment of the Cambridge Astronomical Observatory, and in the founding of the Cambridge Philosophical Society. He was a fellow of the Royal, Royal Astronomical, Geological and other scientific societies. In 1838, and again in 1843, he was one of the commissioners for standards of weights and measures; and he also furnished valuable information to the commissioners on decimal coinage. He died on the 8th of November 1858.
Peacock’s original contributions to mathematical science were concerned chiefly with the philosophy of its first principles. He did good service in systematizing the operational laws of algebra, and in throwing light upon the nature and use of imaginaries. He published, first in 1830, and then in an enlarged form in 1842, a Treatise on Algebra, in which he applied his philosophical ideas concerning algebraical analysis to the elucidation of its elements. A second great service was the publication in the British Association Reports for 1833 of his “Report on the Recent Progress and Present State of certain branches of Analysis.” Modern mathematicians may find on reading this brilliant summary a good many dicta which they will call in question, but, whatever its defects may be, Peacock’s report remains a work of permanent value. In 1855 he published a memoir of Thomas Young, and about the same time there appeared Young’s collected works in three volumes, for the first two of which Peacock was responsible.