that indeterminate forms are never encountered. In particular they may be employed for the calculation of formulas for the impedance (admittance) between the various pairs of terminals of the ideal transformer, when an arbitrary impedance is connected to the remaining pair of terminals; when so used the effects of variations in the value of n and changes in the external circuit impedance (which may vary from zero to infinity) are obtained soZely by giving appropriate values to the variables in these formulas. If an attempt is made to apply such formulas to Weiss's equivalent circuit then, in certain cases, it is found that incorrect results are obtained due to the presence of indeterminate forms. This was illustrated by the example I gave for the calculation of z1 ,2 in my previous letter (I 1. The above criterion of a completely (or perhaps one should say ideal) equivalent circuit requires that even though this circuit has some negative elements, the procedure used in carrying out the steady-state analysis of any network containing this circuit shall be subject to no restrictions than the corresponding analysis of a similar circuit with only positive elements. In this sense I think that my claim that Weiss's equiv- alent circuit is not completely is justified. However, I agree that his circuit is always valid if appropriate analytical methods are used and hence my remark about incorrect results should not have been made as an unqualified statement. In the analysis of large complex networks that contain ideal trans- formers and whose parameters are required to take on arbitrary values, including zero and infinity, it may be difficult to exclude the type. of errors discussed here if Weiss's equivalent circuit is employed. In such cases the use of the writer's more general equivalent circuits would probably be justified. Finally it should be stressed that the writer's motivation in studying this problem was the need to create exact equivalent circuits whose exis- tence would extend the range of theoretical studies involving the node- branch type of circuit analysis. In particular it was required that such