Abstract :
V. Bush (Communicated by letter) : The total power in any network must evidently be supplied by the source. Similarly the algebraic sum of the separate reactive kv-a. in the separate branches must also be supplied from the source as excitation to the system. This applies to a system in which all voltages and currents are of the same frequency, irrespective of how the system may be interconnected. It is a very useful principle, and I have been using it with classes at the Massachusetts Institute of Technology in the form given by Dr. Mershon, since he first called it to my attention sometime ago.
