COSMOGONIC UVi'OTilESES. 233 



of the Earth's rotation ... as to require to be seriously 

 considered in the study of the Earth's deformations." (p. 59.) 



Chaniberhn writes (p. 23) : — " There can be no theoretical 

 doubt that there are tides of the lithosphere." 



Since then Professor A. Young's discovery of lunar-tide 

 effects on the Karoo has been published.* 



Moulton : — " In a word, the quantitative results obtained in 

 this paper are on the whole strongly adverse to the theory that 

 the Earth and Moon have developed by fission from an original 

 mass, and that tidal friction has been an important factor in their 

 evolution. Indeed, they are so uniformly contradictory to its 

 implications, as to bring it into serious question, if not to compel 

 us to cease to consider it as even a possibility." (p. 133.) 



"... The hypothesis of Laplace has the support of no 

 observational evidence. On the contrary, there are well-known 

 considerations . . . which compel us to reject it. . . ." 

 (p. 137.) As to the possibility of the fission-theory of the forma- 

 tion of satellites, planets and double-stars, Moulton's conclusions 

 are : — 



" (I ) We find that the .Sun cannot arrive at this critical stage 

 (fission) until its mean density shall have exceeded 307 X 10" on 

 the water standard. This corresponds to an equatorial diameter 

 of the Sun of about 22 miles. (2) We find that the Sun cannot 

 become so oblate as Saturn is now until its mean density shall 

 have exceeded 148 X io'° on the water standard. . . . Since 

 ■even the latter density is impossibly great, we conclude that tlie 

 Sun will never become so oblate as Saturn is now, and that it will 

 always be more stable than .Saturn is now. 



" (3) We find that Saturn cannot arrive at the critical state 

 at which Jacobian ellipsoids branch, until its mean density shall 

 have become 21 times that of water. . . . We conclude be- 

 cause of the great density demanded that Saturn will never suffer 

 fission." (p. 159. ) " Perhaps the hypothesis that stars are simply 

 condensed nebulae, which has been stimulated by a century of 

 belief in the Laplacian theory, should now be accepted with 

 greater reserve than formerly. Up to the present we have made 

 it the basis not only for work in dynamical cosmogony, but also 

 in classifying the stars. It may be the time is ripe for a serious 

 attempt to see if the opposite hypothesis of the disintegration of 

 matter — because of the enormous sub-atomic energies, which per- 

 haps are released in the extremes of temperature and pressure 

 existing in the interior of suns, and of its disperson in space 

 along coronal streamers or otherwise — cannot be made to satisfy 

 equalh' well-known phenomena. The existence of such a defi- 

 nitely formulated hypothesis would have a very salutary effect in 

 the interpretation of the results of astronomical observations. 

 We should then more readily reach what is probably a more 

 nearly correct conclusion, 77'^.. that both aggregation and disper- 

 sion of matter under certain conditions are important modes of 



* " Tidal Phenomena at Inland Boreholes near Cradock." Trans. Roy. 

 Soc. of South Africa, 1913, Vol. Ill, pt. I. 



