﻿1070 Mr. R. Hargreaves on Atomic Systems 



fluctuation and mean value being greatest for orbits near to 

 the rings. No truly circular orbit is possible, and the inner 

 and outer positions for satellites are in general alternative. 



The cases of B%( + , +) from ?i = 5 to n = 8, in which the 

 closer position is taken, have the advantage of an increased 

 central attraction, for outer satellites certainly. 



The presence of satellites alters in some measure the 

 character of the two rings, which may now be regarded as 

 a type of freely equilibrated nucleus controlling a limited 

 number of satellites. 



As regards the number of satellites there is little doubt 

 that the case of one only is the most important on the 

 ground of freedom from instability ; if internal its relation 

 to the nucleus seems specially intimate. Outer satellites are 

 more exposed to attack but also more readily replaced than 

 inner satellites, when we consider the possible action of other 

 atoms or of free electrons. 



§ 5. The polarizing action of external force is simplest 

 when the force is directed along the axis of the rings, and 

 then brings about a small separation of the planes of positive 

 and negative elements. A force in the plane of the rings 

 gives rise to displacements radial and tangential so nearly 

 balanced in opposite parts of a ring as to yield little resultant. 

 The bond between the rings is sufficiently strong, at any rate 

 when n is not small, to limit the separation of planes to an 

 amount which does not sensibly modify the structure. For 

 satellites the resistance offered to axial force is slight. Again 

 a central ion, though stable axially, suffers a displacement on 

 a sensibly greater scale than the separation of rings. If it 

 is detached by external force it will be subject to attraction 

 by the next neutral structure in its path, may be incor- 

 porated and so move forward by halting steps, functioning 

 as centre for a succession of atoms. The mode of conduc- 

 tion differs from that by free electrons much as electrolytic 

 from metallic conduction ; free electrons have large velocities 

 in random directions modified by external force, while ions 

 move with less velocity but follow more closely the action of 

 external force. There is the further distinctive feature 

 of incorporation at various stages. Cf. § 34. 



An external field of magnetic force in the direction of the 

 axis will give rise to central force in opposite senses on 

 the elements of the two rings. According to the sense of 

 the magnetic field or according to the direction of rotation 

 in the rings, the effect may be to increase or diminish the 

 difference of radii, thus altering the period. 



