243 [chs 



ro = 109.183 X 3962.8 = 432669 miles. 

 p.,^r^ = 92785700 -- 432669 = 214.45 



These results may be compared with those which were given in Notes 

 91, 113 and 156, the extreme range of difference being less than ^'y of one 

 per cent. 



169. Earth's Licipient Subsidence. 



If the various relations which are shown in the foregoing note are due 

 to Earth's atmospheric and nucleal subsidence from the centre of the 



dense belt ( J* = 1.0169394), its secular aphelion should be ( ^ j = 

 1.0695. Stockwell gives (op cit., p. 38) 1.0677352, upon the assumption 

 that — = 368689. On page xi of his Introduction he gives 1.0693888; 

 on page xvii he gives a series of values which yield, by interpolation, 

 1.0691 for the photodynamic mass-ratio, — = 331776. 



170. Progression of Fundamental Atomicities. 



Thomas Bailey, {PJiil. Mag., Jan. 1882, p. 35), gives a series of atomic 

 weights corresponding to minimum volumes, which are membei's of the 

 geometric series a, db, aW, aW, a¥, the value of b being ^ of a and the 

 value of a being 10. This suggests an atomic parabolic motion, like that 

 in the photodynamic or interstellar paraboloid, in which ^ = ^. We may 

 also notice that 6 is the product of the two phyllotactic numbers, 2 and 3. 



171. Perissad Phyllotaxy. 



The indications of phyllotactic tendency in various departments of 

 physics, have induced me to test Gerber's groupings of chemical atoms by 

 methods which seem to me to be perfectly legitimate. In order to remove 

 all effects of personal equation or bias, as well as of accidental or empirical 

 coincidence, I adopt Clarke's recalculation of atomic weights {Phil. 

 Mag. [5] 12, 109-10), and my strictly phyllotactic divisors (Note 

 136), instead of Gerber's empirical divisors. In view of the « p?7m prob- 

 ability of tendency to division in extreme and mean ratio, I assume that 

 the ratio of probability to improbability, in each instance, is equivalent to 

 at least \ D : (T—O) ; D being the phyllotactic divisor, T the theoretical 

 atomic weight or nearest exact multiple of D, and the observed atomic 

 weight taken fi'om Clarke's table. I have added Rb and Tl to Gerber's 

 list of monatomic elements, and Bo to his trivalent list. 



PROC. AMER. PHILOS. SOC. XX. 111. 2e. PRINTED MAY 22, 1882. 



