THOMSON, John Edgar, civil engineer, born in Springfield, Delaware County, Pc.., 10 February, 1808; died in Philadelphia., Pennsylvania, 27 May, 1874. He was the son of John Thomson, the engineer who planned the first experimental railroad in the United States, and was thoroughly trained and educated in the profession by his father. In 1827 he began his own career in the engineering corps that was employed upon the original surveys of the Philadelphia and Columbia railroad, having received his appointment from the secretary of the board of canal commissioners of Pennsylvania, and three years later he entered the service of the Camden and Amboy railroad as principal assistant engineer of the eastern division. In 1832 he was appointed chief engineer of the Georgia railroad, which then controlled the longest line under a single company in this country, and later he was its general manager. In 1847 he became chief engineer of the Pennsylvania, railroad, and in 1852 he was made its president, which office he held until his death. Mr. Thomson took chief charge of the road before it was finished, and during the twenty-eight years of his administration dividends were regularly paid on the stock with the exception of a single semiannual dividend in 1857. When his presidency began, the Pennsylvania company owned 246 miles of road and had a capital of $13,000,0.00; and it has since become a corporation controlling 2,346 miles of railroad and 66 miles of canal, with a capital of $150,000,000. Mr. Thomson possessed remarkable engineering ability and executive skill. He was connected with other railroad enterprises in various parts of the country, and was a director in many companies.