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.