The calculation of air-space flux

With the increase of alternating-current apparatus and the spread of wireless telegraphy, the calculation of airspace flux, whether electromagnetic or electrostatic, becomes daily of greater importance. At present the old formulae of Forbes are used, supplemented by certain cases developed by Maxwell, Thomson, Carter and others. This paper extends the number of these cases, and develops therefrom close approximations in forms of immediate use to the designer. The results thus obtained are compared with the older formulae, by means of examples. The following is a list of the chief cases considered :¿ I. The flux between equal equipotential surfaces in parallel planes. II. The flux between equal parallel equipotential surfaces in the same plane. III. Variation in Case I produced by surfaces like those in Case II. IV. The effect of the outer surfaces of two equal equipotential surfaces in parallel planes. V. The flux issuing from a taper pole-shoe. VI. The flux distribution in a stepped recess. VII. Calculation of capacities by means of the same theorems.