It is a device broadly similar to the mercury-arc lamp produced by Peter Cooper Hewitt.
Another lamp differing widely in appearance from the preceding arcs may be described here because it is known as the mercury-arc.
The circuit of a mercury-arc rectifier charging outfit is shown in Fig. 415.
For example, assume that phosphorescent zinc sulphide is excited by the light from a mercury-arc.
The mercury-arc rectifier proper consists of a glass bulb containing vacuum and a small amount of mercury.