body must necessarily be changed in the way stated, and that the equations of electrodynamics[1] must assume the form stated by Lorentz.
Both authors now also give the equations of motion for an electron deformed in the given way, which essentially differ from Abraham's equations. An application of the equations to my previous measurements by Lorentz, led to the surprising result that my observations can be represented by them with the same precision, as Abraham's equations for the rigid electron.
However, it was shown that the velocity values, which had to individually attributed to the measured curve points to connect them with Lorentz's formula, are smaller by 5-7% than the values according to Abraham's formula. By that, the way was simultaneously given to decide between both theories.
When it could be achieved to determine the velocities belonging to the individual curve points (see below), independently of the electron theory employed, and directly from the constants of the experimental arrangement – in the following denoted as the "apparatus constants" –, and to compare these values with those given by the one or the other theory from the shape of the photographed curve – from the "curve constants" –, then the greater of lower degree of agreement between both systems of value, could serve as criterion for the validity of one of the two theories. Of course it didn't appear to be excluded from the outset, that maybe none of both theory gave a sufficiently precise agreement, or that also other fundamental assumptions could lead to a satisfying result.
Abraham[2] alluded to the fact, that Lorentz's deformation of the electron requires the expenditure of work, so that one has to assume, to avoid a contradiction with the energy law, an "inner potential energy" of
