464 EMERSON— RECURRENT TETRAHEDRAL DEFORMATIONS. 



The remarkably interesting new book by Professor Chamberlin^'^ 

 gives what I had suggested above as desirable and feasible, to wit, a 

 more nebular trend to the planetesimal hypothesis. It makes clear 

 the reality of the forward rotations of a satellite by the interaction of 

 elliptical rather than circular orbits, and builds up with convincing 

 clearness such a simple spiral nebula as would evolve into our solar 

 system. He lets the approaching star exert its disrupting agency 

 on our sun, then larger by the mass of the planets, as a tidal at- 

 traction which sets free the enormous expansive energy of the sun 

 itself so that great masses of incandescent matter — exaggerated 

 protuberances — were thrown off, and thrown off in rotation because 

 of the unequal character of the expelling force. Such masses form 

 the knots on the arms of the spiral nebula and by contraction on 

 cooling initiate the planets. By exaggerating — which he does not 

 do — the size of these knots in relation to the final planet's we get all 

 the advantages without many of the disadvantages of the old nebula 

 theory. 



He then goes on to develop the thesis that the major influence 

 in producing the larger inequalities of the earth's surface has been 

 the variation in the rate of rotation of the earth; thus proposing a 

 supplement or substitute for the tetrahedral hypothesis. 



Starting with the idea that rotation must have had alternate in- 

 creases ; when the equatorial band would bulge and the polar areas 

 flatten ; and decreases when the equatorial band would flatten and 

 the polar areas bulge, there would be a secular seesaw motion be- 

 tween the rising and sinking areas along circular fulcrum lines at 

 30° N. latitude and 30° S. latitude. The tensile stresses during 

 elevation in the polar areas would be relieved (on the law of least 

 action) by three fissures radiating from the north pole at 120° from 

 each other and ending at the fulcrum line. The tensions produced 

 during the following equatorial expansion would be relieved by 6 

 fissures divaricating 2 and 2 from the three ends of the set of fissures 

 above defined, and meeting 2 and 2 at the opposite fulcrum line and 



Indeed a certain parson is reported by Lockyer to have claimed that there 

 might' be areas in space in which miracles were possible and that the earth 

 may have passed through such an area at the beginning of our era. 

 17 " The Origin of the Earth," 1916. 



