60 HISTORY OF ASTRONOMY. 



fhere might be many more similar fragments which, had 

 not yet been discovered. He also inferred, that though 

 the orbits of all these fragments might be differently in- 

 clined to the ecliptic, yet, as they all had a common 

 origin, their orbits would have two common points of in- 

 tersection, situated in opposite regions of the heavens, 

 through which every fragment would necessarily pass in 

 the course of each revolution. He proposed, therefore, to 

 search carefully, every month, the north-western part of 

 the constellation Virgo, and the western part of the con- 

 stellation of the Whale, being the two opposite regions in 

 which the orbits of Ceres and Pallas were found to inter- 

 sect each other. Meanwhile the discovery of a third 

 planet tended to confirm the truth of his hypothesis, and 

 to encourage him in his arduous undertaking. 



Professor Harding, of Lilienthal, undertook to con- 

 struct a series of charts upon which should be represented 

 the positions of all the small stars lying near the paths of 

 Ceres and Pallas, with a view to assist the identification 

 of these minute bodies. On the 1st of September, 1804, 

 while engaged in exploring the heavens for this purpose, 

 he perceived a small star in the constellation Pisces, 

 very near to that part of the constellation of the "Whale 

 through which Olbers had asserted that the fragments of 

 the shattered planet would be sure to pass. On the even- 

 ing of the 4th he re-examined the neighborhood, and 

 found that the star had changed its place. On the 5th 

 and 6th, he observed it more accurately, and finding that 

 the positions deduced from his observations confirmed the 



