Pressure and High Velocity Vapour Jets at Cathodes of a Mercury Vacuum Arc

The amount of vaporization of copper from the cathode of a copper arc measured by Tanberg as well as the velocity of this vapour calculated from the force of reaction on the cathode, agree closely with the values obtained by another method from the cathode of a mercury arc. With a mercury arc and fixed cathode spot the mercury vaporization is 0.017 ×{} 10^-3 gr/amp. sec. and the vapour velocity 16 to 43 ×{} 10⁵ cm/sec.