OH ABERftAliON. 

 On:;f'td\!t the dofc c/hlc. VI. On Akrraticir 



Til PI foregoing projeftion for aberration in right at 

 cenfion and declination, and the rules for the application 

 of the equations in right afcenfiou, are only to be con- 

 fidered as ftridly general tor liars whofe latitudes and 

 declinations are both north. For a ftar whofe declination 

 is north and latitude fouth, or declination fouth, and 

 latitude north ; in place of beginning with the longitude 

 of the ftar, begin with its oppofite, that is with a point 

 iix figns diftant. In the firft cafe the figns muft be laid 

 -off and numbered in a contrary direction to thofe in the 

 projedion which was ufed for ^ Medufse whofe latitude, 

 and declination, were both north : and the aberration in 

 right afcenfion will be pofitive when a point three figns 

 behind the fun's place, falls on the right-hand fide of the 

 meridian of the ftar, the point of right afcenfion being 

 held from you. In the iecond cafe the figns muft be laid 

 off and numbered in the fame progreffive manner as in 

 the projedlion for ^ Medufae, and the fame rules are to be 

 obferved in the application of the equations : But in both 

 thofe cafes, the longitude of the ftar, and its point in 

 right afcenfion, will be fituated on contrary fides of a 

 diameler at right angles to the meridian of the ftar. 

 When the declination, and latitude of the ftar, are both 

 fouth, the projeftion may be made as if they were both 

 north, but the figns muft then be laid off, and numbered in 

 a contrary direftion, and the contrary rule is to be obferved 

 in the application of the aberration in right afcenfion. 



Obfervations 



