Lewis and Adams' Relation ship between h, c, and e. 699 



calculated accurately by considering each element of the 

 field o£ force separately and integrating up, assuming a 

 not improbable distribution of electricity in the spheres, 

 the angular momentum might be' found to be given by 



V lo c 



This expression, if the spheres were shrunken or swollen 

 negative or positive electrons, is that calculated by Leu is 

 and Adams for h (Phys. Rev. (2) iii. p. 92 (1914)). And 

 it might also be found that (2) the energy of the system 

 was 1/c 2 times its mass, (3) that the diameter of the system 

 was e/co, and (-1) that the velocity of the periphery was c. 

 In the case that has been considered the coefficients were not 

 unity. 



.Regarding the physical interpretation of the critical 

 angular velocity, there are two possibilities : (1) The radii 

 of the spheres might be fixed ; if the angular momentum 

 were less than the critical value there would be a tendency 

 for the spheres to fall into one another, if it were greater 

 they would fly apart ; (2) the criterion might be that ihe 

 spheres were always in equilibrium, the centripetal force 

 being equal to the electrostatic force, and this would require 

 that the angular momentum should always have the critical 

 \alue. Accordingly, it is found that the spheres wculd 

 have to decrease in size with increase of energy. It is not 

 quite clear what would cause the spheres to alter their radii 

 in this way, but it is possible that, if there was an inward 

 force which balanced the outward pull on the surface of the 

 tubes of force with an increase in angular velocity, the tubes 

 would lag behind and leave the surface of ihe spheres farther 

 from the normal, and hence, the effective outward pull being- 

 reduced, the spheres would shrink. It is suggested that 

 some such electric doublet, where the distribution was such 

 that the coefficients w T ere correct, is the unit of radiation. 



Space free from all radiation would be considered to 

 contain an infinite number of doublets of infinite size. If a 

 certain volume of space is filed with homogeneous polarized 

 radiations of frequency &), some of these doublets would 

 shrink and rotate with frequency o>, angular momentum 7?, 

 and energy lico. If the radiation were of sufficient density, 

 the whole volume of space would be full of rotating doublets, 

 similar to a train of cog-wheels, the electric force at any point 

 would be varying periodically, and there would be also a 

 magnetic force at right angles to the plane of the rotations of 



