Silver anniversary of symmetrical components

In June 1918 Doctor C. L. Fortescue presented before the Institute the paper, “Method of Symmetrical Co-ordinates Applied to the Solution of Polyphase Networks.” This paper has been recognized generally as having a far-reaching effect in the solution of unbalanced polyphase circuits. Since 25 years have now elapsed, the committee on power transmission and distribution believes that it is of interest and value to review the development and to consider the manner and extent of its effect on electrical engineering.