840 The Philippine Journal of Science 
doubt, that the fundamental K-frequency for helium with only 
one electron is exactly 4.0016 times that for hydrogen. Such 
a close approximation to a very simple relation leads us to infer 
that the actual laws governing the process are very simple. 
Any explanation of the stability of electronic orbits, when 
applied to the frequencies of the K-series, naturally takes the 
form of Bohr’s “constancy of angular momentum,” or something 
equivalent to it. If mur is a constant for this series, the natural 
explanation seems to be that the velocity of propagation of waves 
in the electron ring varies inversely with its radius. The 
K-series electrons, and probably all stable electrons in atoms may 
be considered to contain single standing waves, but Bohr’s 
“outer orbits” of hydrogen, and similar partially stable electro- 
nic conditions would seem to be determined by the presence of 
two, three, four, etc., standing waves in the ring. 
In conclusion I wish to propose the vibrating electron ring as 
a working hypothesis for the stability and definiteness of atoms 
which is entirely consistent with the classical electromagnetic 
laws. 
SUMMARY 
1. The general methods of attack on the problems of the struc- 
ture and properties of electrons have been briefly reviewed. 
2. It has been pointed out that an interpretation of the out- 
standing experimental observations in terms of the classical elec- 
tromagnetic theory leads to the hypothesis of a ring electron 
vibrating internally in standing waves. 
