MOVEMENTS IN THE STAR-DEPTHS. 75 



tion of my views by Dr. Huggins' observations. In 

 his table of stellar motions, Dr. Huggins brackets 

 together the five stars in question as possessing a com- 

 mon motion of recession at the rate of about twenty 

 miles per second. Moreover he finds, from the nature 

 of their spectra, that they are all alike in physical 

 constitution. 



It is hardly necessary to insist upon the importance 

 of this result. It proves, first, that in this instance 

 and therefore presumably in the other instances of 

 apparent star-drift, there is a distinct family or group 

 of stars, travelling bodily onwards amidst the star- 

 depths. It is shown that the motions taking place 

 within this star-family are small compared with the 

 common motion of the group. It can be inferred that 

 the group is relatively isolated, since otherwise we 

 should find other stars in the Great Bear sharing in 

 the motion of these five ; and also, if there had been a 

 disturbing orb at a moderate distance from the group, 

 the members of the family would ere this have lost 

 their uniformity of motion. Whatever may be the 

 centre around which these five stars are moving as a 

 single group, the distance of that centre must exceed 

 enormously the dimensions of the group, precisely as 

 the distance of the sun from Jupiter's satellite family 

 enormously exceeds the dimensions of that system. 

 Yet the distances separating the stars of the Great 

 Bear are themselves amazingly vast. The distance 

 between Beta and Zeta of the Great Bear cannot be 

 less than 100,000 times the distance separating our 



