Unification of linear network theory

The concern of this paper is not so much to present new concepts as to achieve a unification of old ones in a consistent scheme. The theory of linear networks is developed from its fundamental laws in the light of the Principle of Duality. The usefulness of this principle, both in clarifying ideas and in shortening calculations, does not seem to have been adequately appreciated hitherto, and the paper is largely an attempt to emphasise its value. Well-known theorems are considered in relation to the general principle, and some apparently new theorems are proved. At the end of the paper a brief discussion is given of duality in regard to the electromagnetic field.