5$ ON THE NEW PLANET CERES. 



fore the moft favourable time to look for its fatellites, if there 

 are any, to meaftire its diameter; and to examine its nebu- 

 lofity. About this time, the planet will alfo be in its greateft. 

 geocentrical latitude = 17° 9', and a little later (he will have 

 her greateft retrograde motion, about 13 min. in right afcen- 

 fion per day. The north declination will increafe till the be- 

 ginning of April, and about the 9th of the fame month the 

 Variable light of motion in declination will commence to the fouth. It ap- 

 Cercs. peared to me that the Ceres has fome change of light ; I im- 



puted it at firft to our hazy atmofphere this winter,, but Mr. 

 Schroeter of Lilienthal, and Mr. Olbers of Bremen, fent me 

 word that they have obferved the fame, and they believe that 

 it is the plane! which is fubject to fuch changes of light. Mr. 

 Herfchel will tell us belt whether it is fo. I have fome hopes 

 to find the planet in ancient catalogues of ftars. Mr. Melfier 

 was very near it in the year 1779. The famous comet of that 

 year ran jufl over the northern wing of Virgo, as now, and 

 the new planet was not very far diftant. If the comet had at- 

 tained two months fooner the completion of Virgo, Mr. Mel- 

 fier muft infallibly have obferved the Ceres then, becaufe he 

 determined all the little itars in the vicinity of the comet ; the 

 planet would have been in the way of the comet, and fo of 

 courfe he would have catched the little planet in 1799. 



If my obfervations are acceptable to you, dear Sir, only a 

 Jittle hint, and I (hall continue with pleafure to give you fur- 

 ther intelligence. 



I am, 

 with the greateft efteem and regard, 

 very refpecifuIJy, 

 moil honoured SIR, 

 Your obedient humble Servant, 

 FRANCIS BARON DE ZACH. 

 Lieut . Col. and Direclor of Seeberg Obfervatory 

 near Gotha Saxony" 



REMARKS. 

 Remarks. '• The diftance which correfponds to the logarithm of f 



axis major, viz. 0,44.2474-2, is 2,76996*4, the earth's radius 

 being unity. 



2. The whole tropical period from the mean daily helio- 

 centric tropical motion, 769,7924'', is 1683 d 13 h 41' 56,3*. 



3. The 



