698 THE POPULAR SCIENCE MONTHLY. 



urged an immediate advance into East Tennessee. General Buell de- 

 layed, and General Mitchel asked to be relieved. It was not, how- 

 ever, till tlie 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. lie selected the force and wrote the order ; but just 

 at that time concluded to appoint General Halleck his military ad- 

 viser. 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 Caro- 

 lina. 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 judg- 

 ment. 



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 Mili- 

 tary 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 determin- 

 ing 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 de- 

 termination 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- 



