Models of the Aether. 335 



equal and opposite to that of the original filament. As the 

 bodies are moved apart, the hollow vortex may, through failure 

 of stability, dissociate into a number of smaller ones ; and if 

 the resulting number be very large, they will ultimately take 

 up a position of stable equilibrium. The two sets of filaments 

 the original filaments and their hollow companions will be 

 intermingled, and each will distribute itself according to the 

 same law as the lines of force between the two bodies which are 

 equally and oppositely electrified. 



Since the pressure inside a hollow vortex is zero, the portion 

 of the surface on which it abuts experiences a diminution of 

 pressure ; the two bodies are therefore attracted. Moreover, as 

 the two bodies separate further, the distribution of the filaments 

 being the same as that of lines of electric force, the diminution 

 of pressure for each line is the same at all distances, and there- 

 fore the force between the two bodies follows the same law as 

 the force between two bodies equally and oppositely electrified. 

 It may be shown that the effect of the original filaments is 

 similar, the diminution of pressure being half as large again as 

 for the hollow vortices. 



If another surface were brought into the presence of the 

 others, those of the filaments which encounter it would break 

 off and rearrange themselves so that each part of a broken 

 filament terminates on the new body. This analogy thus gives 

 a complete account of electrostatic actions both quantitatively 

 and qualitatively : the electric charge on a body corresponds 

 to the number of ends of filaments abutting on it, the sign 

 being determined by the direction of rotation of the filament 

 as viewed from the body. 



A magnetic field may be supposed to be produced by the 

 motion of the vortex filaments through the stationary aether, 

 the magnetic force being at right angles to the filament and to 

 its direction of motion. Electrostatic and magnetic fields thus 

 correspond to states of motion in the medium, in which, how- 

 ever, there is no bodily flow; for the two kinds of filament 

 produce circulation in opposite directions. 



