Quote:Through discovery, invention, and engineering application, the engineer has made electricity of continually greater use to mankind. The invention of the dynamo first made engine power many times more effective in relieving the toil and increasing the opportunities and comforts not only of industry but also of the home. Its scope, however, was limited to relatively short distances from the power station because of the low voltage of the distribution circuits. This limitation, for economic reasons, kept the general use of electricity confined to city areas where a number of customers could be served from the same power station. The next step in the development of the present-day electric systems was the invention of the transformer. This invention was revolutionary in its effect on the electric industry because it made high voltage and long transmission distances possible, thus placing the engine power, through the medium of the alternating-current generator, at the doorstep of practically everyone.

To 60s power-transmission systems grew tremendously in complexity. Voltages were doubled, longer lines were built, interconnections became more extensive, knowledge of how to protect against lightning was greatly increased, and new methods of calculating performances were adopted. With all this grew the need for a book on transmission lines, one of broader scope that would meet the new conditions, but retain the entirely practical viewpoint of its predecessor. Fourteen men, all connected with the Central Station Engineering Group of the Westinghouse Electric Corporation, undertook to produce such a book. It was presented in January, 1942.

A fourth and completely rewritten edition is presented herewith. It contains essentially the material of the previous three editions, sometimes with new authors, and three new chapters-Excitation Systems, Application of Capacitors to Power Systems, and Power Line Carrier Application.