rations. 



262 ON THE PLANET VESTA. 



convinced me now, that I bad before rae a similar fourth ce- 

 lestial body. 

 Described. The disk of the asteroid which I saw was clear, well de- 



fined, and free from nebulosity. At the first view I was in- 

 clined to believe it a real one; and the Georgian planet 

 being conveniently situate, so that a telescope might without 

 loss of time be turned alternately either to this or to the ast- 

 teroid, I found that the disk of the latter, if it were real, 

 would be about one sixth of the former, when viewed with 

 a magnifying power of 460. The spurious nature of the 

 asteroidal disk, however, was soon manifested by an increase 

 of the magnifying power, which would not proportionally 

 increase its diameter as it increased that of the planet; and 

 a real disk of the asteroid still remains unseen with a power 

 of 636. 

 Farther obser- May 23. The new star has advanced, and its motion is 

 direct ; its situation with respect to the two small stars a 6, 

 is given in fig. 7» 



Its apparent disk with a magnifier of 460 is about 5 or 6 

 tenths of a second ; but this is evidently a spurious appear- 

 ance, because higher powers destroy the proportion it bears 

 to a real disk when equally magnified. The air is not suffi- 

 ciently pure this evening to use large telescopes. 



May 24. With a magnifying power of 577 I compared 

 the appearance of the Georgian planet to that of the aste- 

 roid, and with this power the diameter of the visible disk of 

 the latter was about one 9th or 10th part of the former. The 

 apparent disk of the small star near Leonis, which has been 

 mentioned before, had an equal comparative magnitude, and 

 probably the disks of the asteroid and of the star it resem- 

 bles are equally spurious. 



The 20 feet reflector, with many different magnifying 

 powers, gave still the same result; and being already con- 

 vinced of the impossibility, in the present situation of the 

 asteroid, which is above two months past the opposition, to 

 obtain a better view of its diameter, I used this instrument 

 chiefly to ascertain, whether any nebulosity or atmosphere 

 might be seen about it. For this purpose the valuable quan- 

 tity of light collected by an aperture of 18£ inches directly 

 received by an eye-glass of the front view without a second 



reflection, 



