Page:Zur Theorie der Strahlung in bewegten Körpern.djvu/27

 necessary; though it had to be shown in a complicated way, that the sum of the work, which must be performed at a cyclic process with moving radiating bodies at acceleration and delay, is equal to zero.

The magnitude of the apparent mass, which was calculated by us in § 5, is now modified by this assumed change of volume. However, equation (23) remains unchanged, since this modification lies outside of the limit of precision, which holds for this equations.

, July 1904.

(Received July 28, 1904).