Rationale und nicht-rationale Behandlung des elektromagnetischen Feldes

The question of a rational or non-rational way of writing of equations, definition of quantities and fixing of units is formulated in general and represented for source- and vortex fields. In order to characterize this geometrical alternative, "corresponding coefficients" without dimension are introduced which are to be put equal to 1 or to 4 [pi] in the rational or non-rational case. The transition rational [...] non-rational may be carried out in general according to the method of variation of quantities as weIl as variation of units. The description of the force of attraction between masses being in use since Newton, proves as non-rational. With the help of the principles generally laid down, the problem of the rational or non-rational description of electrodynamics as well as mutual transition from one treatment to another, is explained. For 4 ways of writing most important in practice (rational, partly rational according to Maxwell or Gauss, and non-rational according to Schaefer) a respective set of equations is developed and the concerned scheme of "corresponding coefficients" put up. In addition, the method given here, is compared with the representations made by other authors.