Expulsion protective gaps

@article{Rudge1937ExpulsionPG,
  title={Expulsion protective gaps},
  author={W. J. Rudge and E. J. Wade},
  journal={Electrical Engineering},
  year={1937},
  volume={56},
  pages={1508-1510}
}
EXPERIENCE with the expulsion protective gap since 1932, when the first commercial installation was made, has demonstrated the efficacy of this device as a means of improving service by preventing lightning outages on overhead transmission lines.