\JO NATIONAL ACADEMY OF SCIENCES 



ing this newly-found body excited much discussion among 

 astronomers. 



In 1852, Professor Bache, then Superintendent of the United 

 States Coast Survey, obtained the help of Professor Peirce in 

 preparing the longitude determinations in the Survey, and from 

 the work he then did appears to have originated his article in 

 Gould's Astronomical Journal, entitled " Criterion for the Rejec- 

 tion of Doubtful Observations." " It would seem almost certain 

 that ' Peirce's Criterion,' or possibly some modified form of it, 

 will in time secure general acceptance. In any case, it will ever 

 stand as the first, and as a satisfactory solution of this delicate 

 and practically important problem of probability." 



For seven years Professor Peirce was Superintendent of the 

 United States Coast Survey, having been appointed in 1867 after 

 the death of Professor Bache. While in this position, he made 

 several tours of inspection, and raised the standard of the ser- 

 vice by giving greater freedom to the officers of the corps, plac- 

 ing responsibility on each person engaged in the work, and 

 giving aid to all scientific work connected with the Survey. As 

 Superintendent he took personal charge of the expedition to 

 Sicily in 1870, to observe the eclipse of the sun which occurred 

 in December of that year. By his efforts as a member of the 

 Transit of Venus Commission, a party from the Coast Survey 

 was sent to Nagasaki, and another to Chatham Island, to take 

 part in the observations on the occasion of this important astro- 

 nomical event. 



In 1864, Professor Peirce read his first paper before the 

 National Academy of Sciences, and from 1866 to 1870 a series 

 of papers that were published later in his " Linear Associative 

 Algebra." This work he pronounced " the pleasantest mathe- 

 matical effort of my life," and a writer has said of it that it 

 " must ever remain a monument to the comprehensive grasp of 

 thought and analytical genius of its author." 



Interested in all astronomical questions, and especially those 

 concerning the solar system. Professor Peirce studied the nebular 

 hypothesis, the rings of Saturn, the phenomena of comets and 



