WALKER, Timothy, jurist, born in Wilmington, Massachusetts, 1 December, 1806 ; died in Cincinnati, Ohio, 15 January, 1856. He was graduated at Harvard in 1826, taught mathematics at the Round Hill school, Northampton, Massachusetts, in 1826-'9, studied at Harvard law-school in the latter year and in 1830, and removed to Cincinnati in 1831, where he was admitted to the bar and settled in practice. With Judge John C. Wright he established the Cincinnati law-school in 1833, and when in 1835 it was united with Cincinnati college he assumed entire charge of that department, and was professor of law there till 1844. He was president-judge of Hamilton county court of common pleas in 1842-'3, founded the "Western Law Journal" in 1843, and was its editor for several years, at the same time practising his profession. Harvard gave him the degree of LL. D. in 1854. He translated Fischer's "Elements of Natural Philosophy" (Boston, 1827) ; was the author of " Elements of Geometry" (1828) and " An Introduction to American Law," for students (Philadelphia, Pennsylvania, 1837: revised ed., by J. Bryant Walker, 1869); and delivered several discourses, including "The Dignity of Law as a Profession" (Cincinnati, Ohio, 1837); "On the History and General Character of the State of Ohio " (1838); "John Quincy Adams" (1848); "The Reform Spirit of the Day," delivered before the Phi Beta Kappa society of Harvard (Boston, 1850); and " Daniel Webster," a memorial (1852).--His brother, Nears Cook, mathematician, born in Wilmington, Massachusetts, 28 March, 1805: died in Cincinnati, Ohio, 30 January, 1853, was graduated at Harvard in 1825, and taught near Boston, and subsequently in Philadelphia, whither he removed in 1827. He built an observatory for the Philadelphia high-school in 1837, which was the first of importance in this country except that at Hudson, Ohio, and introduced a superior class of instruments. From its equipment in 1840 until 1852 he published in the "Proceedings" of the Philosophical society and in the "American Journal of Science" the astronomical observations and investigations that he made there. He was employed in the Washington observatory in, 1845-'7, where, on 2 February, 1847, four months after the discovery of the planet Neptune, he identified it with a star that had been observed by Lalande in May, 1795. From 1847 until his death Mr. Walker had charge of the longitude computations of the United States coast survey. With Professor Alexander D. Bache he developed the method of determining differences of longitude by telegraph, which was put in successful operation in 1849, and introduced the chronographic method of recording observations. His parallactic tables, first prepared in 1834, greatly reduced the time in computing the phases of an occultation. He published various astronomical and mathematical papers of value, including "A Memoir on the Periodical Meteors of August and November" (Philadelphia, 1841); "Researches relative to the Planet Neptune" (1850); and "Ephemeris of the Planet Neptune for 1848-'52" (1852). See an "Address in Commemoration of Sears Cook Walker, delivered before the American Association for the Advancement of Science, 19 April, 1854," by Benjamin A. Gould, Jr. (Cambridge, Massachusetts, 1854).