ON THE SATELLITES OF UKANUS. 105 



glimpses of some stars south, but not one of them could 

 lie see for any constancy. 



On the 28th of March, 1797, he observed an ex- 

 cessively small star about four times the distance of 

 the second satellite, which he did not remember to have 

 seen on the 25th. 



On the 16th of February, 1798, a very faint satellite 

 was observed, and from its distance was supposed to be a 

 little before or after its greatest southern elongation. It 

 was so faint that a small alteration in the clearness of the 

 air rendered it invisible. On the 18th this satellite was 

 seen again, and being nearer the planet than it was on the 

 16th, it was supposed to be on its return from the greatest 

 southern elongation. It was also ascertained on the 18th 

 that it had left the place where it was seen on the 16th. 



On the strength of the preceding observations it has 

 been generally admitted that Uranus has six satellites; 

 but Mr. Lassell, during his residence at Malta, carefully 

 scrutinized the neighborhood of the planet to the distance 

 of five minutes from his center, for the discovery of satel- 

 lites. In the course of this scrutiny, he made many 

 measurements and diagrams of the positions of small 

 points of light, which all turned out to be stars, and he 

 adds, " I can not now resist the conviction, amounting in- 

 deed in my own mind to certainty, that Uranus has no 

 other satellites (except four) visible with my eye and optical 

 means. In other words, I am fully persuaded that either 

 he has no other satellites than these four, or if he has, they 

 remain yet to be discovered." 



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