THE PLANET NEPTUNE. 27 



selected from the Histoire Celeste all the stars within a 

 degree of the computed path. These stars were nine 

 in number, of which six had, however, been subse- 

 quently observed by Bessel, and of course were to be 

 set down as fixed stars. But three stars remained which, 

 required special examination ; and of these, one was too 

 small to be mistaken for the planet, and a second was 

 thought to be too far from the computed place. The 

 remaining star was distant only two minutes from the 

 computed place of the planet ; it was of the same mag- 

 nitude, and was not to be found in Bessel's observations, 

 although this part of the heavens must have been in- 

 cluded in the field of his telescope. This discovery was 

 made on the 2d of February, 1847; and on the first 

 clear subsequent evening, February 4th, the great equa- 

 torial of the Washington observatory was pointed to the 

 heavens, and this star was missing. Where Lalande, in 

 1795, saw a star of the ninth magnitude, there remained 

 only a blank. The conclusion seemed almost certain, 

 that Mr. Walker had here obtained the object of his 

 search. He accordingly computed the path upon this 

 supposition, and found that a single elliptic orbit would 

 represent, with almost mathematical precision, the ob- 

 servation of 1795, and all the observations of 1846. 



The case seemed completely made out. But there was 

 a weak point in tfie argument. Lalande had marked his 

 observation of the altitude of this star as doubtful. Could 

 we rest the decision of a question so important upon a bad 

 observation? How unfortunate, that among the 50,000 



