Discussion on “recent investigation of lightning protective apparatus'” at New York, December 28, 1906

Ralph D. Mershon: There is probably no other natural force amongst those with which modern engineering has to deal of which so little is intimately known as of lightning. In most engineering problems it is possible to control and reproduce at will the conditions actually existing in practice, and thus study the phenomena resulting therefrom; or, if this is not possible, there is a natural repetition of the phenomena of sufficient regularity so that they can be studied and traced back to the elements on which they depend. With lightning this is not so. The conditions existing in practice cannot be controlled, and the elements involved are so enormous, numerous, and variable that it is impossible to reproduce them. The natural repetition of phenomena is at such irregular intervals, and the phenomena, when they do occur, are apparently so erratic, due to the number and variability of the elements on which they depend, that no satisfactory searching study has been made of them.