Chase.] 4:10 [June 17, 



tion against uniform resistance varies as the square of the time of com- 

 municating or overcoming the velocity of projection, we find the proportion : 

 Sun's projectile locus or semi-axis major, p^, is to Earth's projectile locus 

 or semi-axis major, p^ as the square of the time of communicating orbital 

 velocity, tj^, is to the square of the time of communicating nascent or dis- 

 sociative velocity, ^^^ Assuming the values, p^^=1.0Qi8r^, ^^ ==214.667ro, 

 in accordance with the foregoing note, and remembering that tn is always 

 the time of a half rotation, we have 



1.0648 : 214.667 : : tj" : 43082^ 

 i;^ = 3034.25 sec. 

 «^ = 3034.25 X 32.088 -- 5280 = 18.44 miles. 

 ^3 = 18.44 X 31558149 ^ 2n = 92,617,300 miles. 



89. Doiible Systems of Photodynamic Oscillation. 



In 1864, I suggested* "that one of the most probable results of the rota- 

 tion of the earth with its atmosphere, in an ^ethereal medium, would be 

 the production of two systems of oscillations, moving with the rapidity of 

 light, one in the line of the Earth's orbit, and the other in the line of its 

 radius vector, and that those systems would be constantly so related that 

 while one tended to retard, the other would tend to accelerate the Earth's 

 motion. " In 1866, I showedf that "the velocity of light is nearly the same 

 as the velocity which would be acquired in one year by a falling body, 

 under the influence of an accelerating force equivalent to the force of 

 gravitation at the Earth's surface." Although I regarded this approxima- 

 tion, at first, as "perhaps merely a curious accidental coincidence," it be- 

 came so prolific in suggestive leadings that I was able to show its depend- 

 ence upon simple dynamic laws of sethereal condensation. From the 

 electrostatic analogies of condensation and the electrokinetic analogies of 

 orbital motion, we may infer the probable applicability of the law of 

 energy and stress of radiation, "that at every point of the wave the intrin- 

 sic energy of the medium is half electrostatic and half electrokinetic. "J 

 At the locus of primitive coincidence between orbital and rotary velocity, 

 this division of energy would lengthen the time of acquiring the solar 

 nascent dissociative velocity of light to a complete rotation of the centre of 

 condensation, the time for the nucleus being a half-rotation. Dividing 

 one year by the square root of the ratio of solar photodynamic projection 

 (Note 88), we find 31558149 seconds h- x/iT0648 — 3058254 sec. ; v^ = 

 3058254^ = 185, 858 miles ; ^3= 497. 827»;^ = 92, 525, 300 miles. This differs 

 by less than one-tenth of one per cent, from the value given in the fore- 

 going note. 



* Proc. Am. Phil. Soc, ix, 408. 



t lb., X, 269. 



t Maxwell, ii, 391. 



