290 NINETEENTH CENTURY. pt. in. 



whether he had not made a mistake ; but at last a young 

 German astronomer named Gauss set to work to calculate, 

 from the facts which Piazzi had given, whereabouts in the 

 heavens the planet ought then to be, and turning his tele- 

 scope to the point, there he found it ! This planet was 

 called Ceres; it was very small compared to the other 

 planets, but the astronomers were satisfied at having filled 

 up the supposed gap. 



Before two years had passed away, however, in the year 

 1802, another astronomer. Dr. Olbers, of Bremen, suddenly 

 announced that he had found ^another Httle planet near 

 Ceres, which he called Pallas, and in 1804 a third was found 

 by another astronomer named Harding, who called it Juno. 

 It seemed very strange that so many bodies should be 

 moving round the sun at nearly the same distance from 

 it, and Dr. Olbers suggested that they might perhaps be 

 parts of one large planet which had broken up into fragments. 

 If this was so he expected to find more, and truly enough in 

 1807 a fourth was discovered, which he called Vesta. In 

 1845 and 1847 two more were added to the number. 

 Since then some have been found every year, till now no 

 less than 153 of these small planets, or asteroids as they 

 are called, are known to be moving round the sun be- 

 tween Mars and Jupiter. Pallas, the largest of these, only 

 measures about 600 miles across, and when it comes nearest 

 to the earth does not look larger than a star of the eighth 

 magnitude. Whether they are really fragments of a planet is 

 not proved, and we have still a great deal to learn about them. 



Encke's Comet, 1819. — The next bodies of interest which 

 were discovered were two returning comets, each of them 

 remarkable for different reasons. The first of these was 

 observed in 18 19, through the telescope at Marseilles, by a 

 Frencliman named Pons. It was very small, and is mainly 



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