7 8 THE POPULAR SCIENCE MONTHLY. 



the prime vertical, and those with the mural circle, it contained 

 various important investigations of the errors and corrections peculiar 

 to the instruments. Prof. Coffin's masterly discussion of the adjust- 

 ments of the mural circle, and his expansion of Bessel's Refraction 

 Tables, Walker's investigation of the latitude of the observatory, and 

 his comparison of the standard thermometers ; all of great value." 



In the second volume reference was made to the discovery of Nep- 

 tune, and the success of Mr. Walker, one of the assistants, in detect- 

 ing, among Lalande's observations, two of Neptune, on May 8 and 10, 

 1795, when the planet was observed and recorded as a fixed star. 

 " Astronomers were thus furnished with an observation of Neptune 

 made fifty-two years before, which afforded the means of a most accu- 

 rate determination of the orbit, and enabled the superintendent of 

 the American Nautical Almanac to publish an ephemeris of the new 

 planet two years in advance of all other parts of the Almanac. The 

 observatory was first brought into prominence by these researches" 

 In October, 1849, Lieutenant (now Rear-Admiral) Davis wrote as fol- 

 lows to the Hon. Secretary of the Navy on this subject : " The theory 

 of Neptune belongs, by right of precedence, to American science. In 

 connection with its neighbor, Uranus, it constitutes an open field of 

 astronomical research, into which the astronomers and mathematicians 

 of the United States have been the first to enter, and to occupy dis- 

 tinguished places." Deprecating heartily though I do, all reference 

 to priority or nationality in such matters as opposed to the true scien- 

 tific spirit, I cannot but note how Prof. New comb, by his admirable 

 researches into the theory of Uranus and Neptune, has fulfilled the 

 hopes thus expressed nearly a quarter of a century before his labors 

 were brought to a successful termination. 



The work of the obsei-vatory, thus happily inaugurated, was prose- 

 cuted steadily till 1861, when Commander Maury left Washington to 

 join the cause of the Confederate States. During the greater part of 

 the war the observatory was under the charge of Captain Gilliss, 

 who died on February 9, 1865. " It has been noted as a strange coin- 

 cidence of circumstances," says Prof. Nourse, in the memoir of the 

 observatory from which we have been quoting, "that the last morn- 

 ing of his life witnessed an announcement of results deduced at this 

 observatory which had fulfilled his long-deferred hope of determin- 

 ing the solar parallax by simultaneous observations in Chili and in ' 

 the United States. This announcement would have been peculiarly 

 gratifying to him because these results were from the joint activity 

 of the two observatories, founded through his exertions, 5,000 miles 

 apart." 



From 1865 to 1867 the observatory was under the superintendence 

 of Rear-Admiral C. H. Davis, and from 1867 to the present time it 

 has been under that of Rear-Admiral B. F. Sands. Without further 

 considering the work accomplished at the observatory itself, which 



