208 FROM NEBULA TO NEBULA 



tional data and found that this movement of the pole can 

 be expressed by a formula containing two terms, one of 

 which varies between 85-1000 and 185-1000 of a second of 

 arc, covering a period of about 430 days, and the other 

 between 115-1000 and 155-1000 sec., whose fluctuating 

 cycle is one year. These displacements, in terms of feet, 

 are respectively between 9 and 20, and 12 and 15 (a sec- 

 ond of arc of the earth's surface being almost precisely 

 100 feet) and they exhibit themselves in the form of min- 

 ute rotations of the pole, produced, like the precessional 

 circle, contra-clockwise. 



In another place I have sought to emphasize the cir- 

 cumstance that since Newton's day many fundamental 

 scientific truths have come to light for which he made no 

 anticipatory provision. Here is a case in point. Had 

 he known of the existence of this phenomenon, in addi- 

 tion to all the other wonderful facts astronomy has un- 

 earthed since his time, it might have occurred to him to 

 consider, at least provisionally, whether the torsions of 

 the sun and moon upon the earth's equatorial ring could 

 not better apply to this problem than to that of preces- 

 sion, for which he did employ them. He might then have 

 raised in his mind the reflection that CYCLICAL CAUSES 

 should produce CYCLICAL EFFECTS, and discarded, before he 

 had gone too far, the absurd hypothesis that the annual 

 attraction of the sun on the earth's ring produces a di- 

 minutive arc of a big circle, rather than the diminutive 

 complete circle it should naturally produce. In the new 

 problem there is pressing need of the very causes Newton 

 thus preempted for precession, but no astronomer dares 

 to broach such a thing as the diversion of them to this 

 new use, because the greater problem of precession 

 would then be revived and make necessary a complete re- 

 construction and readjustment of the whole theory of the 

 science for which drastic course the powers that con- 

 trol are not yet ready. 



So, instead of adopting the true reasons to explain 

 the phenomenon in question, be the consequences what 

 they may, astronomers are groping about for some plau- 



