SKETCH OF M. ARAGO. 265 



Arago published, in the " Annuaire " of the Bureau des Longitudes, 

 popular papers on natural phenomena and on the applications of sci- 

 ence to industry. One of these dissertations was on thunder and 

 thunderbolts. Another, which appeared in 1829, was on the history 

 of the steam-engine ; others were on rain, the cold of night, the ruddy 

 moon, and the influence of the moon on terrestrial phenomena. He 

 also published a paper on eclipses of the sun ; and a total eclipse 

 occurring in July, 1842, which could be favorably seen at Perpignan, 

 he went there to observe it. Notice had already been taken of the 

 aureole which appears around the moon during an eclipse, and to what 

 are now known as the protuberances, and he gave his special attention 

 to them. 



Having been made perpetual secretary of the Academy of Sciences 

 in 1830, he was accustomed to come early to the meeting every Mon- 

 day, where he received foreign savants, read the correspondence, and, 

 if it was his day, began the sitting with an analysis of the papers 

 offered ; and so clear and so much sought for were his analyses, that 

 the memoirs sent up were frequently indorsed "For M. Arago's day." 

 He also accompanied his analyses with a history of the questions dis- 

 cussed and a criticism of the proposed solution, the authority of which 

 was never contested. In a short time this audience, though evidently 

 illustrious, seemed to him too restricted. He desired to extend it. He 

 had found a close Academy, working without witnesses, with doors 

 closed or only half opened to a few privileged persons. He had them 

 opened wide to all the world ; and, in order that science might be 

 spread more rapidly and further, he invited journalists to attend the 

 meetings, and provided a place for them where they could take notes. 

 He further, in 1835, induced the Academy itself to publish its proceed- 

 ings under the supervision of the perpetual secretaries ; and this was 

 the origin of the famous " Comptes Rendus." 



As a deputy and member of the political body, Arago proposed a 

 scheme for damming one of the arms of the Seine and establishing a 

 system of turbine pumps by which Paris should be fully supplied 

 with water, which was defeated by a ridiculous jest. He induced the 

 municipal council to bore the Artesian well of Grenelle, which was a 

 great wonder in its day. He secured a public recompense for Vicat, 

 who had invented an economical hydraulic cement. And when Da- 

 guerre came forward with his wonderful invention, which made it 

 possible to take an exact portrait, by the aid of the sun, in fifteen 

 minutes, Arago explained the method before the Academy and ex- 

 pounded its capabilities. 



While a member of the Legislative Assembly, Arago was attacked 

 with a malady which resulted in a gradual loss of sight, that became 

 total in 1852. Being unable to make further researches, he endeav- 

 ored to gather up and reduce to form the unfinished work of his past 

 career. The visible results of this effort were seven conferences which 



