THE TIDES AND TIDAL ROTATION 89 



due to the faet that the farther south the sun, the greater 

 the water expanse he has on which to operate, and the 

 more telling his effect. 



A spectacular object-lesson in atmospheric tides, 

 which nevertheless has hitherto been lost upon science, 

 is that of the comets, whose tails, when present, are in- 

 variably directed away from the sun. Current theory 

 persists in regarding 1 this behavior as an infraction of 

 the law of gravitation, and seeks to explain it by a fan- 

 tastic theory. of light, or electrical, repulsion. The sim- 

 ple and natural explanation is, that when far remote 

 from the sun, the comet, being for the time compara- 

 tively relieved from perturbing external strains, draws 

 itself up into a ball and wraps its ethereal cloak evenly 

 about itself. But later, as it nears the sun again, his 

 increasing attraction compels it to keep lowering its 

 center of gravity more and more (the better to preserve 

 its balance in its mad rush through space) and, con- 

 versely, to relegate its tenuous gases in the diametri- 

 cally opposite direction, which is to say, a way from the 

 sim. Whatever mystery the phenomenon possessed dis- 

 appears instantly in the light of the rule that heavenly 

 bodies attract each other by their centers of gravity and 

 not of figure, and that the comet and the system to 

 which it belongs are both gravitational units. 



I must not close this chapter without correcting an 

 error, as inexplicable as it is universal, in regard to the 

 imaginary tidal action on molten bodies, an error too 

 which lies at the very base of various modern theories 

 of cosmogony which are even now aspiring to public 

 favor. According to this notion, third bodies are formed 

 by two sun's approaching each other sufficiently near 

 to tear each other to pieces by tidal strain. This is 

 sheer nonsense. A star's integral power is at its maxi- 



