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been that it did not yield the inverse square law of electrostatic attraction 
at extremely small distances. If, as Professor Whittaker infers, the electric 
field about the atom is not permanent, but is evoked by the approach of 
an electron, the same should hold with regard to an approaching a particle, 
and a reconsideration of the prevailing views seems to be demanded. 
§ 4. If I am right in attaching physical significance to tubes of magnetic 
induction, it becomes important to trace the distribution of the tubes in 
such a case as is presented by Professor Whittaker’s magneton. Regarding 
the model as a wheel with a S-pole at the hub and N-poles distributed 
round the rim, the lines of force starting from the rim would curve round 
and enter the wheel at its centre. The number, N, of the tubes is given 
by N = 47 tM, where M is the total pole strength (of one sign) for the 
different bar magnets which form the spokes of the wheel. Now, in 
equation (9) Professor Whittaker obtains the expression 
Aw = 2eM , 
that is to say, the angular momentum of the wheel is 2eM or ^Ne. But 
according to the quantum theory angular momentum can be expressed as 
Wi/27t, where n is an integer. So we find at once 'N = n(Ji/e), or the total 
number of magnetic tubes associated with the magneton is an integral 
number of times the fundamental quantum tube defined by hje, in exact 
agreement with the results I have obtained previously in other cases. 
It may be noted that the angular momentum is independent of the size 
of the magneton. 
The general arrangement of the lines of magnetic force in the model is 
not unlike that which would occur if two thin anchor rings, representing 
the magnetons either of McLaren or of Parson, were placed near together 
with their planes parallel and having a common axis. Thus, if we think 
of Professor Whittaker’s magneton as a bicycle wheel, these rings would be 
represented by the two beaded edges of the rim. But to obtain the required 
distribution of the lines of magnetic force the rings must be placed so that 
the magnetic force between them is one of repulsion. It would of course 
be possible to introduce an electrostatic attraction to balance this repulsion 
by supposing one ring to be charged positively and the other negatively ; 
and it may be worth noticing that such an arrangement is not unlike that 
pictured by Professor Whittaker in the latter part of his paper. 
l^Added May 13, 1922. — I am indebted to Professor Whittaker for 
pointing out in the discussion on May 8 that the two ring electrons, 
* H. S. Allen, Phil. Mag., vol. xlii, p. 523, 1921. 
