36 HISTORY OF ASTRONOMY. 



the name of a law. A law of nature is precise it is 

 capable of exact numerical application. Let, then, the 

 preceding rule be called the law of Bode ; it is not a law 

 of nature. 



It was at first the opinion of some observers, that 

 Neptune is surrounded by a ring like Saturn. Mr. Las- 

 sell, of Liverpool, has an excellent Newtonian reflector 

 of twenty feet focal length, and two feet aperture, with 

 which he has made numerous observations of the planet. 

 On the 3d of October, 1846, he was struck with the 

 shape of the planet, as being not that of a round ball ; 

 and again, on the 10th of October, he received a distinct 

 impression that the planet was surrounded by an ob- 

 liquely situated ring. On the 10th of November the 

 planet appeared very much like Saturn, as seen with a 

 small telescope, and low power, though much fainter. 

 Several other persons also saw the supposed ring, and 

 all in the same direction. During the season of 1847, 

 Mr. Lassell frequently saw the same appearance again, 

 and found its angle of position to be 70 degrees S. W. 

 He also satisfied himself that this appearance did not 

 arise from any defect in his telescope. 



Professor Challis states that on the 12th of January, 

 1847, he received for the first time a distinct impression 

 that the planet was surrounded by a ring. Two inde- 

 pendent drawings, made by himself and his assistant, 

 gave the annexed representation of its appear- 

 ance. On the 14th, he saw the ring again, and 

 was surprised that he had not noticed it in his 



