MISCELLANEOUS PROBLEMS 133 



This process of planetary schooling is bound in 

 time to shorten the period of comets, so that we be- 

 come altogether relieved from the peril, though peril now 

 no longer, of hypothesizing the existence of a resisting 

 medium just in order to explain their vagaries, as, for 

 example, the acceleration of Eucke's comet. Further- 

 more, it demonstrates why comets, as such, are so short- 

 lived. For one thing, the imprisoned gases will even- 

 tually all be liberated, thus shearing away the comet's 

 beautiful tresses; and, for another, approximation to 

 orbital circularity will increasingly tend to abate the 

 comet's internal commotion, and thereby render it non- 

 luminous and consequently invisible. 



SATURN'S RINGS 



Should the comet by chance have one great dom- 

 inating ball in its composition, with a mass consider- 

 ably excelling the combined mass of all the other par- 

 ticles, the result Avill be a system like that of the sun 

 or Jupiter. And if we go a little further, and imagine 

 the small particles discrete and close to their primary, 

 we shall have a miniature Saturn, though hardly lumi- 

 nous, since the minuter the particles the sooner will 

 they lose their inflammable gases. In Saturn's case, 

 however, the rings are so dense, and the friction due to 

 the differentiation of the orbital speed of, and the elbow- 

 ing for position among, the constituent particles, is so 

 great, as possibly to raise the rings to the point of in- 

 candescence and keep them so. 



NEW AND VARIABLE STARS 



Our sun, I take it, is a variable star with a period- 

 icity corresponding to its maculae period. The cause, 

 I believe, is due to a sort of "knot" in its otherwise 

 homogeneous constitution, which with approximate 



