280 Proceedings of the British Association for 1850. 



occupying the very place in our system where the anticipated 

 planet ought to have been found. Ceres, the first of these? 

 was discovered by Piazzi, at Palermo, in 1801 ; Pallas, the 

 second of them, by Dr Olbers of Bremen, in 1802 ; Juno, the 

 third, by Mr Harding, in 1804 ; and Vesta, the fourth, by 

 Dr Olbers, in 1807. After the discovery of the third, Dr 

 Olbers suggested the idea that they were the fragments of a 

 planet that had been burst in pieces ; and, considering that 

 they must all have diverged from one point in the original 

 orbit, and ought to return to the opposite point, he examined 

 these parts of the heavens and thus discovered the planet 

 Vesta. But though this principle was in the possession of 

 astronomers, nearly forty years elapsed before any other plane- 

 tary fragment was discovered. At last, in 1845, Mr Encke of 

 Driessen, in Prussia, discovered the fragment called Astrasa, 

 and in 1847 another, called Hebe. In the same year, our 

 countryman, Mr Hind, discovered other two, Iris and Flora. 

 In 1848, Mr Graham, an Irish astronomer, discovered a ninth 

 fragment, called Metis. In 1849, Mr Gasparis of Naples, 

 discovered another, which he calls Hygeia ; and within the 

 last two months, the same astronomer has discovered the 

 eleventh fragment, to which he has given the name of Par- 

 thenope.* If these eleven small planets are really the re- 

 mains of a larger one, the size of the original planet must 

 have been considerable. What its size was would seem to 

 be a problem beyond the grasp of reason. But human genius 

 has been permitted to triumph over greater difi&culties. The 

 planet Neptune was discovered before a ray of its light had 

 entered the human eye ; and by a law of the solar system 

 just discovered, we can determine the original magnitude of 

 the broken planet long after it has been shivered into frag- 

 ments ; and we might have determined it even after a single 



