156 FROM NEBULA TO NEBULA 



annual loss in position with respect to the stars of 50".2; 

 and since the anomalistic year is longer by 12" of arc 

 than even the sidereal one, it follows that the perihelion 

 advances, not merely 12", but 12"+50".2 annually. In 

 short, the time of the revolution of the earth's apsides is 

 not the apparent period of 108,000 years, as till now sup- 

 posed, but 



360 



g^ =20,900 years (about) 



The periods of the other planets, to be derived by the 

 same method, should therefore hereafter form our bases 

 of comparison and correlation. In passing, be it noted, 

 one consequence of this interpretation is to take Venus 

 out of the category of exceptions (in which it has stood 

 alone) and include it in the general rule, namely, that the 

 perihelia of all the planets advance. 



THE STAB STREAMS SO-CALLED 



The reader may infer from what has just been dis- 

 cussed that the star streams that Kapteyn was the first 

 to call attention to, may find their explanation in this 

 principle. Such is not my own opinion. This phenome- 

 non of star-streaming is, like the daily motion of the 

 heavens around our earth, illusory. It is only apparent. 

 It arises from a misguided attempt on the part of astron- 

 omers to generalize from data gained by observing 

 from one moving body another moving body with refer- 

 ence to a third moving body, all of whose velocities and 

 distances, relative and absolute, are highly conjectural, 

 and, in the case of the earth at least, misconstrued. No ! 

 whoever cares to play the role of skipper of this good 

 ship, Earth, and in imagination will take his stand at her 

 south pole and sail her around the sun's orbit a voyage 

 or two, watching the while the stars on shore, will soon 

 come to realize that the supposed streams are but the 

 optical effect of our change of position. 



