RECENT COSMOGONIES 197 



densation, form stars and systems. The clusters, like the whirl- 

 pool nebulae, have a tendency to spiral movement. 



It will be remembered with what scrupulous care 

 Newton strove to impress upon the world the notion that 

 cosmic space is absolutely clear of any ponderable 

 medium. Why? Because he recognized, even if his suc- 

 cessors affect ignorance of it, the absolute necessity, 

 under his theory, that the infinitely accurate adjustments 

 between gravity on the one hand and the tangential veloc- 

 ity of the circulating body on the other, ordained, as he 

 postulated, by the Creator, dare not on any account be 

 altered, even in the slightest, without immediately and 

 irretrievably destroying (not merely imperiling) the 

 whole system. Since his day, however, a few phenomena, 

 such as the moon's acceleration and the acceleration of 

 Encke's comet, have come to light that have put the 

 mathematicians sadly at a loss to explain gravitationally, 

 save on one perilous assumption, namely, that the ether, 

 or some other cosmic medium mingled with it, is opposing 

 the free passage of the revolving bodies. 



It may strike the lay reader as paradoxical to be told 

 that the acceleration of an orbitally revolving body can be 

 explained by its retardation, but the acrobatic astronomer 

 of to-day is equal to any emergency. His explanation is, 

 that a body so retarded in its orbit is thereby forced to 

 fall to a lower level, where, he tells us, under the mystical 

 law of conservation of areas, "it is natural for bodies to 

 move and revolve faster than at greater distances. ' ' Not 

 only, says he, does the resisted body miraculously re- 

 cover the velocity lost, but it actually acquires a tangen- 

 tial velocity greater even than at first! Such is "celes- 

 tial ' ' mechanics ! 



In addition to thus cajoling themselves into believing 

 that retardation makes for speed, just as Lane persuaded 

 them that the sun, by cooling, becomes all the hotter, our 

 learned doctrinaires, proceeding along the same lines, 

 have succeeded in convincing themselves that a concomi- 

 tant effect of this process is to cause the orbit of the re- 

 tarded body to become more and more rounded. 



