A Calculation of the Orbit of the Comet. 105 



able to pursue them, to the extent which might be desir- 

 able. Those who have more leisure, may at any time 

 enter on a more minute and precise investigation. It is 

 probable however, that the errors of the observations 

 will exceed those of the calculation I have made, in their 

 effects on some of the deductions. The following are 

 the results of that calculation. 



Place of the ascending node, 8* 27** 08' 



Place of perihelion, 8 28 48 



Inclination of its orbit to ecliptic, 63 09 



Perihelion distance, that of the earth ') ^AAc^r. 

 p ., I • 1 e- .64480 



Irom the sun bemg 1, 5 



Time of being in perihelion, Sept. 18th, 12h. 40m. p. m. 



Time of its being in ascending node, Sept. 17th, 3h. p.m. 



Motion of the comet, direct. 



Remarks. This comet approached the sun from 

 the regions of the south, and first became visible to an 

 inhabitant of the earth, about the 25th of July last. From 

 that time, it might have been seen by those who live in 

 places of considerable south latitude ; but on account of 

 the great inclination of its orbit to the ecliptic, and its 

 little elongation in longitude, during all the time of its 

 approaching to, and part of that of its receding from the 

 sun, it could not be seen by the inhabitants of Europe, 

 or of the United States, till towards the end of Septem- 

 ber. After this, its elongation, in north latitude, was in- 

 creased, so as to give it an elevation above the horizon, 

 which caused it to be visible after sun-setting. It dis- 

 appeared to the naked eye, about the beginning of No- 

 vember, but was discernible with a telescope towards 

 the end of that month. 



From a comparison of the elements as above stated, 

 with those of 78 comets observed by European astrono- 

 mers, during the two or three last centuries, it does not 

 appear, that this comet is one of that number. That of 

 1684, calculated by Dr. Halley, agrees nearest with this, 

 in all the elements, except that of perihelion distance ; 

 but this alone, if the numbers, as deduced by that great 

 astronomer, be correctly stated in the books to which I 

 have had access, is a decisive evidence, that they are not 



O 



