Among these services, in 1849 ne undertook the revision of the American 

 Ephemeris and Nautical Almanac, for which he prepared his valuable lunar 

 tables. In 1855 he was one of the commission to organize the Dudley 

 Observatory. From 1867 to 1874 he was in charge of the United-States 

 Coast-Survey, and rendered great service to the country and to science by 

 recruiting the languishing financial strength of that service, and impressing 

 upon Congress the duty of effectually re-organizing and pushing forward the 

 work so much retarded by the civil war. He was one of the original mem- 

 bers of the National Academy. He threw all his influence into the organiza- 

 tion and successful development of the American Association, which he 

 always held should be free from class distinctions, and to which he would 

 never be elected in the higher class of fellows, but was a member only. He 

 contributed very largely to make the American Academy of Boston what it 

 is; and throughout the whole of the scientific literature of the past fifty years 

 Peirce's name frequently occurs as a contributor upon mathematical and 

 physical topics. In his own department of the University he thoroughly 

 impressed the concise methods of thought so effectually used in his greater 

 works. The teaching at Harvard is based upon his methods and notation, 

 and these methods are models of perspicuity and elegance. In physical 

 astronomy perhaps his greatest works were in connection with the planetary 

 theory, his analysis of the Saturnian system, his researches regarding the 

 lunar theory, and the profound criticism of the discovery of Neptune follow- 

 ing the investigations of Adams and of Leverrier. As a mathematician, his 

 work on Analytical Mechanics, his treatise on Curves, Functions, and Forces, 

 and his memoir on Linear Associative Algebra, all evince extraordinary 

 originality and genius. Many of his detached papers, relating to the theory 

 of observing, and the solution of special problems, show an appreciation of 

 the needs in applied mathematics which perhaps has not been exhibited by 

 the same order of genius since the death of his friend and admirer, Gauss. 

 His originality was fostered by his habit of examining a new mathematical 

 question for himself, and only referring to the work of other geometers after 

 he had first fairly exerted his own powers of analysis. 



His genius was early recognized abroad ; and elections to the Royal Socie- 

 ties of London, Edinburgh, and Gottingen, and to various Continental socie- 

 ties, were awarded him. The versatility and breadth of his mind is partly 

 shown by the scope of his papers ; but to those who came in daily contact with 

 him he showed such a penetrating discernment of the conditions of a problem, 

 he made such sagacious suggestions regarding the inferences to be drawn 



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