5^4 Reflcdlons on the new Phirjef. 



(3*071) '• = 5"38t7 years. By the tifual melhods. I obtained 

 the following approximate elements of the orbit : 

 Eixjch of the mean heliocentric longitude 



for the commencement of 180 1 

 Long, of the afceiiding node 

 jNIcan annual motion _ _ _ 



Inclination of the orbit . - - 



Semidiametcr of the orbit 3"07i 

 Svnodical revolution - 5*38015 



Thofe who attentively conlider and compare thefe elements 

 will no doubt remark, that the diltance and periodical time 

 of Piazzi's liar are esaclly the fame as tliofe of the celebrated 

 comet of 1770, the calculation of which gave fo much em- 

 plovment to aftronomcrs, and the orbit of which Lexel could 

 110 otherwife reprefent than in an elliple of 5 j- years. Pingre 

 alfo found its diliance - 3*09, and the period of revolu- 

 tion 5*4 vears *. Burckhardt, w ho lately obtained the fe- 

 cond prize propo fed on this fubjett by the National InlUtute, 

 could not reduce this fingular body from new obfervatious 

 into any other than an elliptical orbit <jf ^i^ years. Was the 

 comet of 1770 the fo long concealed planet ? or was Piazzi's 

 Har the comet of 1770? In either cafe, whether ii was a 

 oimet or planet, Why was it not oftener feen, or before 

 tlifcovered r The caules, fome of which we, have already 

 mentioned, may have been various. But to confine myfelf 

 to a probable way of explaining this point, let the reader only 

 look into Schrciter's Oblervaii^ns on the Comet of 1799, 

 publidied in the third volume of his Coileclions in regard to 

 the lateft Aflronomical Difcovenesi', The moll fingular phje- 

 nomena of the accidental variable modifications of the ne- 

 bulous light furrounding the comet, and alio the well-known 

 atmofphercs of the planets, and even the fun, will be found 

 there explained. In the nebulous light which furrounded 

 the comet of 1799, Mr. vSchroter obfervcd not only occa- 

 fional, but fudden and difproportionably great changes botii 

 in the extent and flrength of the pholofphcrc. Dr. Herfchel 

 not long ago prefented to the Royal Society a paper on the 

 itrufture ot the fun, in which this eminent aftronomer ex- 

 plains the folar fpots by fuppofing an elaflic and not lunii- 

 jious gas difengaged from the opake furface of the fun's body, 

 which divides the furrounding luminous fluid or photofphere, 

 bv v\hich means we tlien fee dark parts of the body, which 

 vv'e confider as fpois. 



Is it not therefore poffible that we fee ftars ;jt one time 



'■ Cometographie, parr ii. p. Sg. 



■t" Alli^ciVi. Gc'Ji^rapli. Ej)hciiii.ncl, vol. iji. p. 432. 



which 



