On the Star Polaris. 21 



which take place between the equator and the poles, the burning 

 heat of the torrid zone, and the intense cold of the frigid, ori- 

 ginate from one universal cause. 



Lvnn, Jan. 11, 1815. Ez. Walker. 



[To fie continued.] 



IV. On the Star Polaris. By Gavin Lowe, Esq. 



To Mr. Tilloch. 



Sir, — X HE annexed table contains the precession, abberation, 

 nutation and solar variation, both in right ascension anddeclina-. 

 tion of Polaris, for the year 1815. It has been computed with 

 great care, and will serve with sufficient accuracy to the year 1 S20. 

 The mean right ascension and declination of that star from 

 1815 to 1820, appear, from the Ijest observations, to be as fol- 

 lows : 



H. M. S. 

 Jan. 1, 1815, mean ill 55 50-22 



1816, 56 4-24 



1817, 56 18-;32 



1818, 56 32-46 



1819, 56 47-07 



1820, 57 01-34 



Decl. 88 19 17-15 



19 36-57 



19 56-01 



20 15-43 

 20 34-85 

 20 54-26 



The general rule for finding the corrections that are to be ap- 

 plied to the mean right ascension and declination of the star, 

 isj to enter the table with the sun's longitude, which is given for 

 every day in the year in the Nautical Almanac, and take out the 

 precession and aberration in the 2d and 4th columns of the 

 table. In like manner with the longitude of the moon's node, 

 had from the same Almanac, take out in columns 3 and 5 the 

 nutation. Apply these corrections respectively to the star's 

 mean riglit ascension and declination, and tlie apparent right 

 ascension and declination are obtained. 



Although the table gives the corrections only for every 10^ of 

 the sun's longitude or maon's node, it is easy to make "propor- 

 tion, and find them for each degree. 

 I am, sir. 



Your most obedient servant, 

 Islington, Dec. 29, 1811. Gavin Lows. 



B 3 ji Table 



