196 Memoir of the Life and Writings of M. Piazzi. 



of the observer, and any imperfection in his instruments. He 

 felt, also, that if Flamstead, Mayer, and Lemonnier, had re- 

 peated their observations more frequently, they might have 

 anticipated Herschel in his great discovery of the Georgian 

 planet. 



Under the influence of these views, Piazzi frequently re- 

 sumed his observations on the same star, before he considered 

 its position as fixed, and after having practised for ten years, 

 this laborious method of observation, he published in 1803, 

 his first great catalogue of 6748 stars, under the title of SteU 

 larum inerrantium positiones. This work was crowned by the 

 Academy of Sciences of France, and gained for its author 

 the admiration and esteem of all the astronomers of Europe. 



Among the results of that catalogue, we may mention one, 

 which formed a new era in astronomy, viz. the discovery of a 

 new planet. 



While Piazzi was examining, on the 1st January 1801, 

 the 87th star of the zodiacal catalogue of Lacaille, between 

 the tail of the Rani and the Bull, he occasionally observed a 

 star of the eighth magnitude. His practice of verifying the 

 observations of the preceding day, led him to observe a differ- 

 ence in the position of this small star, which he at first took 

 for a comet. He communicated his observations to Oriani, 

 who, observing that this luminous point had none of the nebu- 

 losity of comets, and that it continued stationary and retro- 

 grade within a very small space like the planets, calculated its 

 elements on the hypothesis of a circular orbit. This result 

 was confirmed by other astronomers, and Piazzi was invested 

 with the honour of adding a new planet to the system. Piazzi 

 continued to observe it till the 12th of February, when a dan- 

 gerous illness compelled him to discontinue his observations. 



In compliment to his Royal patron, and in imitation of Sir W. 

 Herschel, Piazzi gave to the new planet the name of Ceres 

 Ferdinandea. The King of Naples resolved to consecrate this 

 illustrious discovery by striking a gold medal, containing the 

 head of the astronomer, but Piazzi requested that the value 

 of this present should rather be employed in purchasing an 

 equatorial instrument for his observatory. 



