The frequency of occurrence and the distribution of lightning flashes to transmission lines

A STUDY of Franklin´s correspondence on the subject of electricity shows his clear perception of the proper function of a lightning conductor; he also discusses such still controversial problems as bonding and the relative advantages of vertical rods and horizontal wire systems. On the other hand, no direct reference^∗ as to the protective ratio of a vertical conductor could be found in his papers. Although this question was raised shortly after the introduction of the lightning conductor and has been discussed ever since, no general agreement so far has been reached. In what follows, this problem will be investigated from a new angle, and it will be shown to be even more involved than has been recognized hitherto.