THE POPULAR SCIENCE MONTHLY.
urged an immediate advance into East Tennessee. General Buell delayed, and General Mitchel asked to be relieved. It was not, however, till the President determined to use him in a special service that he ordered him to report at Washington.
Mr. Lincoln proposed to send an army down the Mississippi under his command. He selected the force and wrote the order; but just at that time concluded to appoint General Halleck his military adviser. When General Halleck arrived at Washington he declined to appoint General Mitchel to this command. For two months he was unemployed, and in September, 1862, was sent, by General Halleck's order, to the then quiescent Department of the South, in South Carolina. Here he died of yellow fever on the 30th of October, 1862. His term of military service was fourteen months. During this time he found but one opportunity to act upon his own uncontrolled judgment.
Professor Mitchel was born in Union County, Kentucky, August 28, 1810. At twelve years of age, having acquired a tolerably fair knowledge of Latin and Greek and the elements of mathematics, he became a clerk in Miami, Ohio, but afterward removed to Lebanon, in the same State where he had been educated. He entered the Military Academy at West Point in June, 1825, having himself earned the money with which he was enabled to reach the school. After being graduated in 1829, he became acting Assistant Professor of Mathematics in the Academy, and served in that capacity for two years. He then removed to Cincinnati, where he practiced law till 1834, when he became Professor of Mathematics, Philosophy, and Astronomy, in Cincinnati College, a position in which he remained for ten years, or till the college-building was burned.
Of the more important features of his work at the observatory, "Nature" says, in an article on "Observatories in the United States" (July 9, 1874): "At the request of Professor Bache, the telegraph company connected the observatory with their stations for determining longitude, Cincinnati being then a central point in such work. The astronomer royal, under whose instruction Mitchel had passed three months in 1842, urged, in an encouraging letter, that 'the first application of his meridional instruments should be for the exact determination of his geographical latitude and longitude, and that his observing energies should be given to the large equatorial.' With this advice, he directed his attention largely to the remeasurement of Struve's double stars south of the equator.
"Airy and Lamont had invited him to make minute observations of the satellites of Saturn, since in the latitude of Cincinnati the planet is observed at a more favorable altitude than at Pulkova, twenty degrees farther north. To these, and chiefly 'to the physical association of the double, triple, and multiple stars,' he gave his close attention. He made interesting discoveries in the course of this re-