Abstract :
FOR some time it was hoped that the present active research in atomic nuclear physics would solve many of the unknown phenomena connected with the electric arc, especially the arc in vacuum, and that this would clarify some of the phenomena of the rectification process in a vacuum tube. However, in spite of the fact that little progress was made in applying the latest theories to the practical application of rectifiers, nevertheless, a considerable step forward was made during the last few years in the design of large electronic glass and metal tubes.
