and Velocity of the Solar Motion. 207 
lustre ; yet imperfect as this may be, it is at present the only 
rule we have to go by. 
The relative brightness of our six stars, may be expressed 
as follows : Sirius Arcturus - Capella 7 Lyra - - Alde- 
baran . Procyon. 
The notations here used are those which have been ex- 
plained in my first Catalogue of the relative Brightness of 
the Stars ; * but to denominate the magnitudes of these six 
stars so that they may with some probability represent the 
distances at which we should place them according to their 
relative brightness, I must introduce a more minute subdi- 
vision than has been commonly admitted, by using fractional 
distinctions, and propose the following arrangement. 
Table VIII. 
Proportional Distances of Stars . 
Sirius - 
1,00 
Lyra 
1,30 
Arcturus 
1,20 
Aldebaran - 
1,40 
Capella - - 
1,25 
Procyon - - 
1,4° 
The interval between Sirius and Arcturus is here made 
very considerable ; but whoever will attentively compare to- 
gether the lustre of these two stars, when they are at an equal 
altitude must allow that the difference in their brightness is 
fully sufficient to justify the above arrangement. 
The order of the other four stars is partly a consequence 
of the distance at which Arcturus is placed, and of the com- 
parative lustre of these stars such as it has been estimated by 
observations. But if it should hereafter appear that other 
* Phil. Trans, for 1796, page 189. 
