had examined and verified Leverrier's labors sufficiently to establish their 

 marvellous accuracy and minuteness, as well as their herculean amount. 



A few years later, 1851 to 1855, Peirce published the remarkable results of 

 his labors upon Saturn's rings. Professor G. P. Bond had seen the ring 

 divide itself and re-unite, and had thereby been led to show by computation 

 from Laplace's formula: that the ring could not be solid. Upon this Peirce 

 investigated the problem anew, and showed that the ring, if fluid, could not 

 be sustained by the planet ; that satellites could not sustain a solid ring, but 

 that sufficiently large and numerous satellites could sustain a fluid ring, and 

 that the actual satellites of Saturn are sufficient. 



Jn 1849 he was appointed consulting astronomer to the American Epheme- 

 ris and Nautical Almanac, and rendered efficient service in bringing that 

 publication to its condition of honorable authority; particularly in the lunar 

 tables which he furnished, in his treatment of Neptune, and various methods 

 of computation. He also assisted Professor Bache in the Coast Survey, and 

 was, for many years, of great service in that important national work, before 

 he was himself appointed superintendent in 1867. His calculations of the 

 occultations of the Pleiades were very laborious and exact, and furnished an 

 accurate means of studying the form, both of the earth and her satellite ; his 

 criterion for rejecting doubtful observations is an ingenious and valuable ex- 

 tension of the law of probabilities to its own correction; his detection of the 

 mental error of lurking personal preferences for individual digits is a curious 

 specimen of that acuteness of observation which characterizes his own mind. 



He held the office of superintendent of the Coast Survey from 1867 to 

 1874. Coming after such able men as Hassler and Bache to an office which 

 required not only familiarity with mathematics and physics, but also great 

 knowledge of men and executive ability, he was not found wanting, but 

 showed that the theory of the Stoics will sometimes hold good to-day, the 

 really great man shows himself great by any and every standard. The Coast 

 Survey has, since the year 1845, steadily advanced in public favor ; and its 

 work commands the highest respect among all men competent to judge 

 throughout the world, as being not only of direct service to the nation, but 

 as making constant valuable additions to science. 



Many monographs, bearing the marks of Peirce's individuality and pecul- 

 iar power, have been read by him before various academies, societies, and 

 institutions; but only the results of most of them have ever been furnished 

 for publication. Among these may be mentioned an investigation of the 

 forms of stable equilibrium for a fluid in an extensible sack floating in anoth- 



