Vectors and Vector Diagrams applied to the Alternating Current Circuit

Abstract

NOT many years ago a certain type of journalist used to compare and contrast the theorist and the practical man, to the demolition of the former and the apotheosis of the latter. Fortunately, such an attitude of mind is no longer possible. The merely practical man could never have constructed the Forth Bridge, nor launched the Mauritania on her record-making career. Innumerable examples might be given of the necessity of true theory in the economical designing of all kinds of machinery; but probably there is nothing that better proves how much mathematical science lies at the foundation of modern methods than electrical applications, especially those that have to do with the alternating current. The whole history of the development of the transformer and the alternating-current motor is simply the realisation of the solution of a differential equation given long ago by Maxwell. In this realisation the first great steps were taken by Heaviside, who introduced the terms impedance, admittance, reluctance, &c., giving a new precision to the ideas involved. By a mathematical extension of meaning the symbols which entered into the electrical equations of steady currents became applicable to the corresponding cases of sinusoidal currents. Stated in purely mathematical language, this transition depended on the properties of the complex variable.

Vectors and Vector Diagrams applied to the Alternating Current Circuit.

By W. Cramp C. F. Smith. Pp. xvi + 252. (London: Longmans, Green and Co., 1909.) Price 7s. 6d. net.