Some fundamental characteristics of mercury vapor apparatus

The characteristic of the type of mercury vacuum apparatus, invented and developed by Mr. Peter Cooper Hewitt, which distinguishes it most clearly from other forms of vacuum tubes, is its power of passing a comparatively large continuous current with a constant and comparatively insignificant voltage loss. There are, of course, other important features of this mercury vapor apparatus characteristic to it, such as the negative electrode starting resistance; the disintegrating, reconstructing negative electrode, etc.