JOO, 
A NEW FOUNDATION FOR ELECTRODYNAMICS. 
By ARTHUR W. CONWAY, M.A., F.R.U.I. 
[Read Junr 16, 1903. ] 
Our experimental knowledge of electricity can be divided into three groups— 
electricity at rest, electricity in slow motion, electricity in rapid motion: motions 
being spoken of as slow or rapid according as their velocities or accelerations are, 
or are not, comparable with the velocity of radiation. In the first group we have 
the phenomena of electrostatics ; in the second we have those of currents, and 
probably magnetism ; in the last group we have all the phenomena which appear 
to depend on the rapid motions of electrified corpuscles, either in orbital motions 
about one another, as in an incandescent gas, or else moving in a more direct 
path, as in a vacuum tube. Externally these motions produce the effect called 
radiation. ‘l’o propose a theory which would include all these effects has been 
the object of numerous scientists. The older writers on electricity, such as Gauss, 
Weber, Neumann, sought for the law of force between two electrified particles, 
which would include the well-known law of force between two electrified particles 
at rest, and which would give the proper action between two currents regarded 
as being made up of moving electrified particles. In the treatise of Maxwell 
there is a gap between electrostatics and the theory of currents; whilst the latter 
is connected with the theory of radiation by reasoning which is open to objection. 
Helmholtz assumed for the electric force (X, Y, Z) the expression 
—V* (3/da, d/dy, 0/02) »—V? d/at(F, G, H), 
where f=e/r, e denoting the electric charge and 7 the distance of the point at 
TRANS. ROY. DUB. SOC., N.S., VOL. VIII., PART III. L 
