COLOUR OF THE STARS. 23 



and Benetnasch. This star, it is true, had a special use : it 

 served the Arabs as the test of a good eyesight. 



A further proof that the Arabs founded their stellar nomen- 

 clature almost exclusively upon the lustre and colour of the 

 stars, is obvious in the names which they gave to the stars 

 forming the constellation of Orion. (See Fig. 2.) Thus, a 

 and $, two stars of the first magnitude, occupying the right or 

 eastern shoulder, and the left or western foot of the giant- 

 hunter, are called respectively, Betelguese and Rigel ; the 

 star 7, named Bellatrix, in the left shoulder, is of the second 

 magnitude, like the stars 5, g, <, which represent Orion's Belt, 

 and bear the names of " the Three Kings " and " St James's 

 Staff." Now the star TJ, marking the right knee or inferior 

 eastern angle of the brilliant trapezium, is only of the third 

 magnitude ; therefore, it has received no special designation. 



The colour by which some stars are distinguished could not 

 have failed to be remarked by those observers who first began 

 to enumerate, or take census of, the celestial bodies. Thus 

 Sirius, the most refulgent of the stars of heaven, situated in 

 Canis Major, is of a bluish-white, like Rigel ; and Arcturus, 

 situated on the prolongation of the tail of Ursa Major, is 

 reddish-yellow, like Betelguese. 



Sirius, or the Dog-star, rose heliacally at the hottest time of 

 the year, and hence the Greeks were accustomed to ascribe 

 all the diseases of the season to its influence. It was 



" The star 



Autumnal ; of all stars, in dead of night, 

 Conspicuous most, and named Orion's dog : 



