Medium separating Electrified Particles. 365 



from the aether at the instant the negative cell passes out 

 through the surface, hut perhaps rather at the instant that it 

 comes out from the molecule. In other words, energy may 

 be regarded as flowing in through the surface, but is only 

 absorbed and converted into kinetic energy when it passes 

 into a molecule. 



9. Maxwell has calculated the enormous pressure along the 

 lines of force and the equal tension at right angles to them 

 required, according to his theory, to account for the attraction 

 of the earth by the sun. A minimum value for the amount 

 of energy in one cubic centimetre of gravitational aether 

 can be calculated by finding the negative energy-density 

 on the surface of the sun considered as a body of uniform 

 density. * 



The volume of the energy-cells at any point is _ _. 



The intensity of the gravitational field on the surface of 



M 

 the sun is H e =— -„ where M is the mass and r the radius of 



T 



this body. If p is the density of the sun the volume of an 

 energv-cell is 



4td a 4tt?' 4 9 



2^2 



M 2 (fTrpr 3 ) 2 V 



The amount' of energy lacking in each of these cells is half a 

 unit. Hence one cubic centimetre of aether lacks ^7rp' 2 r' 2 

 units. These are static units of energy. One dyne equals 

 1*544 x 10 7 static units of force, therefore one erg equals 

 1*544 x 10 7 static units of energy. Take r as 6370000 x 

 100 x 110 centim. and p as 1*39. Then the density of nega- 

 tive energy at the surface of the sun will be 



2ttx1*39 2 x637 2 x110 2 x10 12 



. - . , — r-= ergs per c.c. 



9 1-514 X 10' & r 



= 4*289 X 10 u ergs per c.c. 

 = 42*89 X 10 6 joules per c.c. 

 = 16 horse-power hours per c.c. 



This would seem to mean that, at a distance from all gravi- 

 tatino; matter, a cubic centimetre of aether contains at least 

 this amount of energy. 



10. That the theory may require an even greater energy- 

 density than this is seen as follows. Suppose the energy 

 of the gravitational aether to be due to vortex filaments or 

 tubes of directed energy interlacing in every direction. 

 Take at any point three axes at right angles to one another. 



