ACCOUNT OF THE NEW PLANET CERES. T \05 



fheir fufpicions. Some time afterwards, Mr. Lalande -firft 

 obtained a complete copy of the observations of Mr. Piazzi, 

 who cOuld not refufe them to one, under whom he had fo long 

 .applied to the ftudy of agronomy. By means of thefe obfer- 

 vations, I was the firft that demonftrated, in a memoir pre- 

 fented to the National Inftitute, that there was no parabolic 

 orbit that could agree with the obfervations, although con- 

 fined to an arc of 10 degrees. I gave at the fame time the 

 elements of a circular and of an elliptic orbit, and I mowed 

 the great uncertainty that necefTariiy remains when the ele- 

 ments are deduced from fo fmall an arc. 



Having received a more exact copy of thefe obfervations, Elements of its 

 Mr. Olbers endeavoured to determine from them the elements or lC 

 of an elliptic orbit; but he found fo much uncertainty that he 

 was obliged to prefer a circular orbit, fince he thought it im- 

 poilible to determine if the planet was near its aphelion, or its 

 perihelion. I had proceeded on the former fuppofition ; Mr. 

 Gaufs preferred the latter, and endeavoured at the fame time 

 to accommodate his calculations to all the obfervations of Mr. 

 Piazzi : and this he performed with a difference of only a few 

 feconds. Thefe are his elements : 



Epoch of 1801 * - 2s 



Aphelion - - - 10 



Node - - 2 



Inclination - 



Greateft equation of the centre 



Heliocentric and tropical diurnal motion 



Mean diilance 2.7673. E 



Revolution 1 68 1 days, or 4 years 7 months. 



I had found the revolution 5 months and' a half fhorter. 



According to M. Lalande's calculations, Mr. Gaufs's ele- 

 ments give the longitude greater by a degree than Mr. Olbers's 

 obfervation : according to Mr. von. Zach, my elements give 

 it four degrees lefs, and Piazzi's, ten degrees lefs than the 

 obfervation. 



The idea of fearching for this planet among the immenfe give the power 

 collection of obfervations of the Hiftoire Celefte Francaife, of fearch ing for 

 could not fail to prefent itfelf to all thofe who have attended t\&££t* 

 to the fubjecl : but it was impoffible to undertake the inquiry obfervations. 

 with any hopes of fuccefs, before the elements were corrected 

 by new obfervations. I thall now apply to it without delay. 



2 Mr. 



