260 THE POPULAR SCIENCE MONTHLY. 



twelve years his senior, who was destined to he his co-worker or rival, 

 according to circumstances, during his life. In 180G he and Biot were 

 appointed by the emperor to co-operate with the Spanish commission- 

 ers, Chaix and Rodriguez, in continuing the measurement of the arc of 

 the meridian, for the establishment of the metric system. In this ex- 

 pedition he found arduous work, and underwent hard sufferings from 

 the fortunes of war, the story of which we will let M. Jamin tell fur- 

 ther along. He returned to France in the summer of 1809, and was 

 received into the Academy of Sciences, in departure from its rules, at 

 the age of twenty-three years. The emperor, who always manifested 

 a remarkable esteem for him, considering how he had behaved when a 

 school-boy, appointed him Professor of Analysis and Geodesy in the 

 Polytechnic School, a position, or the equivalent of which, he held for 

 twenty years. He also became director of the observatory and de- 

 livered lectures on astronomy, which were heard with equal interest 

 by astronomers and by persons who knew nothing of mathematics, and 

 were fully understood by the latter. 



In 1830 he took the place of Fourier as perpetual secretary of the 

 Academy, in which position it became his duty to pronounce eulogies 

 upon deceased members, the felicity of the style and the scientific 

 accuracy of which gained for him a world-wide reputation. 



In 1830 M. Arago became a member of the Chamber of Deputies 

 for the Pyrenees - Orientates. He took his seat on the Extreme Left, and 

 became a conspicuous advocate of measures tending to the extension 

 of public liberty and to electoral reform. He "was also prominent in 

 discussions relating to the marine canals, public instruction, and rail- 

 roads. When the revolution that expelled the Orleans dynasty took 

 place in 1848, M. Arago was made a member of the provisional gov- 

 ernment by popular acclamation, and was given charge of the bureaus 

 of the marine and of war. He took part in all the events of that 

 stirring epoch, sat among the moderate members, opposed the most 

 radical republicans, while he always enjoyed their respect, was a mem- 

 ber of the executive commission appointed by the Constituent Assem- 

 bly, and marched to the barricades at the head of his troops during 

 the bloody days of June. But so many struggles and shocks had 

 broken his physical and moral energies, and he afterward sat in the 

 Legislative Assembly without taking an active part. He declined to 

 take the oath to the new government in 1852, as inconsistent with his 

 past acts and professions, and was excused from it, and was allowed to 

 keep his place in the observatory unsworn. He died in the next year, 

 October 2, 1853. 



The scientific, personal, and social aspects of Arago's life have 

 been admirably portrayed by M. Jamin in his eulogy, and most of 

 what follows on those points is drawn from that address. The first 

 scientific labors coming under his notice were in association with Biot, 

 the continuation of Borda's investigations of the indices of refraction 



