COLBURN, Zerah, mathematical prodigy, born in Cabot, Vermont, 1 September, 1804; died in Norwich, Vermont, 2 March, 1840. When only six years old he began to manifest extraordinary powers of computation. His father, wishing to make money by exhibiting the boy, left Vermont with him in the winter of 1810-'1. The offer of Dr. Wheelock, president of Dartmouth, to educate Zerah at his own expense was rejected, and the lad was placed on exhibition in Boston, where he attracted much attention. He mentally solved problems involving the use of numbers containing four or five places of figures with greater ease and rapidity than that to which experienced mathematicians could attain. The question, "How many days and hours in 1,811 years ?" was answered correctly in twenty seconds. At this time he could not explain his processes; but a few years later he was able to do so, and it then appeared that he had no new methods, but merely possessed wonderful facility in using the ordinary ones. When he was nine years old he was able to solve questions like the following: "What is 999,999.2 x 492 x 25 ?" The result occupies seventeen places of figures. He immediately gave the factors of 294,967,297, which French mathematicians had supposed to be a prime num-bet. His performances show that his mental processes were inconceivably rapid, and his memory very powerful. After exhibiting his son in the middle and southern states, Mr. Colburn took him to England, Scotland, and Ireland, and finally placed him in the Lycee Napoleon at Paris, where he remained for eighteen months. In 1816 they were reduced to poverty in England, and Zerah attracted the attention of the Earl of Bristol, who placed him in Westminster school for three years; but a disagreement between Mr. Colburn and the earl caused the boy's removal from the school in 1819, and, in accordance with his father's suggestions, Zerah began to study for the stage. Abandoning this, he became assistant in a school, and soon began teaching on his own account, performing astronomical calculations at the same time for Dr. Thomas Young, then secretary of the board of longitude. After his father's death in 1824 he returned to the United States, and, after teaching for a few months in Fairfield, New York, removed to Burlington, Vermont, where he studied at the University, and supported himself by teaching French. He united with the Methodist church in 1825, was for nine years an itinerant preacher, and in 1835 became professor of languages in Norwich University, Vermont. His remarkable faculty for computation left him about the time he reached manhood. Mr. Colburn's manners were unassuming, and he gave no evidence of great ability, aside from his early talent for calculation. He published his "Memoirs" (Springfield, 1833).--His nephew, Zerah, engineer, born in Saratoga, New York, in 1832; died in Massachusetts, 4 May, 1870, lost his father when a child, and removed with his mother to New Hampshire, where he worked on a farm. He afterward went to Boston, found employment in the Lowell machine-shop in 1847, and then on the Concord railroad, where he showed great talent for practical mechanics. He soon rose to be superintendent of Mr. Souther's locomotive-works in Boston, and afterward held a similar place in the works at Paterson, New Jersey, where he invented improvements in freight engines. He then connected himself with the " Railroad Journal," and in 1854 established in New York City the " Railroad Advocate," which he sold in 1855, and bought lands in Iowa. He visited England and France, and gave an account of the machine and iron works there in letters to the " Advocate." In 1857, with Mr. Holley, he again visited Europe at the request of several railroad presidents, and in 1858 they published a report on European railway systems and machinery. They resumed their researches in 1858, in which year Mr. Colburn began writing for the London " Engineer," and soon became its editor. After several years of hard work he returned to the United States and began the publication of an American " Engineer" in Philadelphia. Only a few numbers were issued, and he soon resumed the editorship of the London paper. In 1866 he established in London a new journal called " Engineering," which he continued to edit until a few weeks before his death. In 1870 overwork and irregularity of habits drove him into partial insanity. He came back to this country in April, avoided all his old friends, strayed away to a country town in Massachusetts, and died there by his own hand. During his residence in London, Mr. Colburn was employed as consulting engineer on many important constructions, and prepared numerous valuable papers in addition to his editorial labors. The more noted of these were his papers before the Institution of civil engineers (of which he was a member) on "Iron Bridges" and on "American Locomotives and Rolling Stock," both of which received medals. He was considered a high authority on all subjects connected with mechanical engineering. He published "The Locomotive Engine "(Boston, 1851), and wrote a supplement on "American Practice" for a new edition of Clark's " Locomotive Engine" (1859).