1.8.C. 42  Procs. of the Asiatic Soc. of Bengal. [N.S., XVIII, 
the Sun. 
rof. Eddington has made a comprehensive research 
of stars known to us in this corner of space, are more lumi- 
the luminosity decreases with spectral type—from the blue 
stars down to the red—the stars of late type of spectrum being 
all dwarfs. 
has also found a great mean radial velocity for the faint stars in 
the neighbourhood of the Sun. We shall have occasion to 
return to this point later. 
The Motions of Stars. 
Next to direct measures of Stellar distances, the most 
valuable data are furnished by their motions, of which our 
knowledge may be considered to be at present more extensive. 
The movements of stars are readily resolved into two compo- 
nents, one in the line of sight and the other in the transverse 
direction—the two being found by different methods. 

