i876.] ^^'^ [Chase. 



furnish the following approximations to the rotation velocity, the unit be- 

 ing one ten-billionth of Sun's radius : 



Spttrer, maximum. Nebular action. Light action. Schwabe. SpOrer, minim. 

 295B3 29192 28623 28511 27863 



According to the same indicator, the present height of possible solar 

 atmosphere, or the radius of equal centripetal and centrifugal solar force 

 should be (214.86)1 r = 35.873 r ; the time of planetary revolution at 

 Sun, lyr -=- (214.86) ^ = 10020.242 sec. ; the present limit to the velocity of 

 constant pressure, 27:r -^ 10020.242 = .000627049 r per s; the present solar 

 modulus of light, (.4316 h- .000627049)2?- = 473755.65 r ; the present 

 modulus atmosphere, 35.873 X 473755.65 = 16995141r. 



1 



If we locate the Stellar-solar paraboloid by a vertex at — solar 



radius, (the primitive locus of complete association), and an abscissa 

 (,Cjg.g^3 = 35.873 X modulus) at the present surface of modulus-atmos- 

 phere, the general equation, ^^ z=^ ^ yj ^ ''^ r n-^ furnishes 9 abscissas 



between Sun and Mercury, and 9 between Neptune and a Centauri, the 

 central 9 representing points of dissociating planetary velocity (VIII), as 

 will be seen by the following table of secular elements : 



36.873 aCen. 7.6622 7.6571 7.6860 



The tabular logarithms for a Centauri (7.6571 and 7.6860) represent, 

 respectively, the least and greatest estimates of its distance that have been 

 made. The values of the secular planetary perihelia and aphelia are 

 taken from Stock well's "Memoir on the Secular Variations of the Ele- 

 ments of the Orbits of the Eight Principal Planets" (Smithsonian Con- 

 tributions, 232, pp. 37, 38). 



It is of course impossible, under the present limitations of our knowledge, 

 to determine to what slight extent the foregoing calculations should be 

 modified, by allowances for orbital eccentricity and other considerations. 

 It seems likelj', however, that the parabolic abscissas (X) are the fittest 

 representatives of primitive nebular condensation and retardation, while 

 the forces of constant pressure within the primitive nucleus furnish the 

 closest approximation to the ultimate light-activity. If this opinion should 



PROC. AMER. PHILOS. SOC. XVI. 98. 3m 



