AT HUDSON OBSERVATORY. 



151 



and the longitudes were referred to the mean equinox of January 1, 1840, by 

 applying the precession and nutation. 



The perturbations remained to be computed. In this operation I followed 

 the method of Bessel for the comet of 1807. I employed intervals of eighteen 

 days, the middle days of the several intervals being February 9th, February 

 27th, and March 16th. The values of A, B, and C for their dates, being the 

 united effects of the planets Mercury, Venus, Earth, Mars, Jupiter, Saturn, 

 and Uranus, expressed in ten thousand millionth parts of a unit, are as follow : 





A. 



B. 



c. 



February 9, 



— 115342 



— 39226 



+ 64303 



27, 



— 81595 



— 61489 



+ 36573 



March 16, 



— 104112 



— 76746 



+ 25572 



hese are deduced 











A'. 



B'. 



c. 



February 9, 



+ 22805 



+ 132129 



— 31608 



27, 



— 44625 



+ 98296 



— 11076 



March 16, 



— 98327 



+ 83979 



— 25737 



Hence were computed the variations of the elements of the comet's orbit for 

 each interval of eighteen days, and from them the total amount of variation 

 from January 31st to March 25th. The perturbations in longitude and lati- 

 tude were thence deduced for January 31st, February 18th, March 7th, and 

 March 25th, from which were obtained, by interpolation, the perturbations for 

 intermediate dates. The following is the result : 





Longitude. 



Latitude. 



January 31, 



0".0 



0".0 



February 12, 



.0 



— 1 .1 



23, 



— .2 



— 1 .9 



March 3, 



— 0.4 



— 2 .3 



13, 



— 0.7 



— 2 .5 



24, 



— 1 .1 



— 2 .7 



Applying these corrections with opposite sign to the comet's observed places, 

 we obtain the places such as they would have been observed had it not been 

 for the disturbing action of the planets. The following table exhibits the 

 comet's corrected places, together with those of the earth for the same times, 

 from the Nautical Almanac. 



