766 
MR. J. LARMOR OR A DYNAMICAL THEORY OF 
We have hitherto chosen to take the vortex-atoms with vacuous cores, so that the 
currents must be represented by the vortex sheets on their surfaces ; and this was in 
order to have an extict representation of the circumstances of perfect conductors. If 
we assigned a rotating fluid core, devoid of elasticity, to the vortex-atom, not many 
essential differences would be introduced. The circumstances of an ordinary electric 
current flowing steadily round a channel which is not an ideal perfect conductor are 
somewhat more closely represented by supposing the channel to be the core of the 
ring, filled with fluid whose rotation is uniform across each section ; this uniform dis¬ 
tribution of the current across the channel is however primarily an effect of viscous 
retardation, due to the succession of discharges across intermolecular aether by which 
the propagation is effected. 
Electrostatic Induction hetiveen Aggregates of Vortex-atoms. 
63. When a piece of matter is electrified, say by means of a current conducted to 
it liy a wire, what actually happens according to dynamical analysis on the basis of 
our energy-function, is that an elastic rotational displacement is set up in the aether 
surrounding it, the absolute rotation at each point representing the electric displace¬ 
ment of Maxwell. If there is no viscosity, i.e. if the matter and the wire are 
supposed to be perfect conductors, this result is a logical consequence of the assumed 
constitution of the aethereal medium ; and of course the circumstances of the final 
eijuilibrium condition are independent of any frictional resistance which may have 
opposed its development, so that the conclusion is quite general 
We may now construct a representation of the phenomena of electrostatic induc¬ 
tion. A charged body exists in the field, causing a rotational strain in the aether all 
round it; consider the portion of the mther inside another surface, which we may 
suppose traced in the field, to lose its rotational elasticity as the result of instability 
due to the presence of molecules of matter; the strain of the aether all round that 
surface must readjust itself to a new condition of equilibrium ; the vortical lines of 
tlie strain will be altered so as to strike the new conductor at right angles,—and 
everything will go as in the electrostatic phenomenon. But there will be no aggre¬ 
gate electric charge on the new conductor; for the electric displacement [f, g, li) is a 
circuital vector, and therefore its flux into any surface drawn, wholly in the aether, 
to surround the new conductor, cannot alter its value from null which it was before. 
Now suppose a thin filament of aether, connecting the two conductors, to lose its 
rotational elasticity ; the conditions of equilibrium will again be broken, and the 
effect throughout the medium of this sudden loss of elasticitv will be the same as if a 
wave of alternating vorticity were rolling along the surface of this filament from the 
one conductor to the other, with an oscillation backwards and forwards along it which 
will persist unless it is damped by radiation or viscous action. The final result, after 
