The equation $V=A+(\frac{B}{{I}^{n}})$ for normal arc characteristic curves has been verified and the temperature range over which $n$ has been found to be proportional to the absolute temperature of the boiling point of the anode material has been extended to include the zinc arc in argon at 1180\ifmmode^\circ\else\textdegree\fi{}K with 0.345 for $n$ and the tungsten arc in air at approximately 5100\ifmmode^\circ\else\textdegree\fi{}K with $n=1.38$.