'5^ Refult tf the Obfervatlms 



fecond, I dLfcribed mechanicallv my firft parabola ; and ap- 

 plying to it the longitudes and latitudes thus calculated and 

 obferveJ, it was ealy for me to afcertain that the motion of 

 this ftar could not, indeed, be reprefented in the arc of a pa- 

 rabola fuch as is nearly defcribed by comets. 



III. From parabolic hvpothcfes I proceeded to circular, 

 and, having made a few fuppofitions, f found two radii, viz. 

 27067 and 3-6862, with each of which the obfervations 

 could be reprefented much better than with anv parabola^ 

 for, as the planets dcfcribe ellipfes more or lefs eccentric, 

 and not circles, it is to be fuppofed that our planet will not 

 deviate from this law. I ought therefore to have continued 

 my calculations on an elliplis; but as the obferved arc was 

 very fmall, the refults would have been uncertain, and the 

 labour tedious and painful. On this account 1 preferred the 

 circle, efpecially as the element.s obtained from the eUipfe to 

 determine the place of this (lar do not appear to me to be 

 more certain than thofc adbrded by the circle. 



IV. On the loth of Januarv the Itar, from being retro- 

 grade, became direft. Setting out, therefore, from the ob- 

 lervations of this day, I endeavoured to find its elongation 

 while ftationary, "which was 4' 4*^; whonce we have for mean 

 radius of its orbit 2-93^^3. But the difference between thia 

 radius and the other, obtained by the motion of the ftar be- 

 tween the ift of Januarv and the Tilh of February, feems to 

 indicate a great eccentricity, whereas the feries of the ob- 

 fervations feems rather to indicate that the eccentricity ought 

 to be fmall : on the other hand, the diameter, deduced from 

 the elongation of a^ planet while ftationary, can never be veny 

 exa<ft, and particularly in the prefcnt caie. 



V. During the iirll obiervatioiis, bringing the ftar under 

 the horizontal thread of the telefcope, it remained, as it 

 were, entirely covered; and, as the thread fubtends to the 

 eye an angle of about 6", I judged the diameter of the ftar 

 to be foniewhat greater, that is to fav, 7^^^. Uurine the laft 

 obfervations I was not able to form anv judgment oTits dia- 

 meter, on account of the darkened ftate of the almofphere. 



VI. RESULTS. 



Radius of the orbit - _ _ 2'6863 



Motiou in the orbit from January ill to 



February ijth 

 Epoch 1 80 1 

 Motion in 100 days 

 Longitude S - - 



lucliaation of the orbit . - - ■ 



