Discussion on “some simple examples of transmission line surges” (Franklin), Washington, D. C., April 24, 1914. (see proceedings for April, 1914)

J. Murray Weed: The steepest wave fronts which are produced in the practical operation of electrical systems are those caused by the sudden making or breaking of a circuit. A discharge to ground would come under this classification, although this may not constitute the making of a circuit which it is desired to make. It does not seem likely, however, that the making of a circuit, which takes place by the rupturing of air, oil, or some other dielectric, would result in the rectangular waves which are presented in Dr. Franklin´s paper. When we consider the velocity of 186,000 miles a second, it becomes obvious that a phenomenon which is instantaneous, so far as our ability to measure time is concerned, may distribute its effects over a very considerable length of a transmission line. Furthermore, it is my belief that if, by any means, a perfectly abrupt or sheer wave front were produced in a transmission line, it would be very rapidly decomposed, and that at a considerable distance from the point of its formation it would have become considerably tapered.