DISCOVERY OF JUNO AND VESTA. 



consistent with the hypothesis of their origin advanced by 

 Dr. Gibers. 



9. A year and a half elapsed before any further discovery was 

 produced to favour this hypothesis. Meanwhile, observers did 

 not relax their zeal and their labours, and on Sept. 1, 1804, at 

 ten o'clock, P.M., Professor Harding, of Lilienthal, discovered 

 another minute planet, which observation soon proved to agree 

 in all its essential conditions with the hypothesis of Olbers, 

 having a mean distance very nearly equal to those of Ceres 

 and Pallas, an exceptional obliquity of 13, and a considerable 

 eccentricity. 



This planet was named Juxo. 



Juno has the appearance of a star of the 8th magnitude, and a 

 reddish colour. It was discovered with a very ordinary telescope, 

 of 30 inches focal length and 2 inches aperture. 



10. On the 29th of March, 1807, Dr. Olbers discovered another 

 planet, under circumstances precisely similar to those already 

 related in the cases of the former discoveries. The name VESTA 

 was given to this planet, which, in its minute magnitude, and the 

 character of its orbit, was analogous to Ceres, Pallas, and Juno. 



Yesta is the brightest, and, apparently, the largest of all this 

 group of planets ; and, when in opposition, may be sometimes 

 distinguished by good and practised eyes without a telescope. 

 Observers differ in their impressions of the colour of this 

 planet. Harding and other German observers consider her to 

 be reddish ; others contend that she is perfectly white. Mr. Hind 

 says that he has repeatedly examined her under various powers, and 

 always received the impression of a pale yellowish cast in her light. 



11. The labours of the observers of the beginning of the century 

 having been now prosecuted for some years without further results, 

 were discontinued ; and it is probable that but for the admirable 

 charts of the stars which have been since published, no other 

 members of this remarkable group of planets would have been 

 discovered. These, however, containing all the stars up to the 

 9th or 10th magnitude, included within a zone of the firmament 

 30 in width, extending to 15 on each side of the celestial equator, 

 supplied so important and obvious an instrument of research, that 

 the subject was again resumed, with a better prospect of successful 

 results. It was only necessary for the observer, map in hand, to 

 examine, degree by degree, the zone within which such bodies are 

 known to move, and to compare, star by star, the heavens with 

 the map. When a star is observed which is not marked on the 

 map, it is watched from hour to hour, and from night to night. 

 If it do not change its position, it must be inferred that it has been 

 omitted in the construction of the map, and it is marked upon it 



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