A direct current electric arc has been developed as a heating device for argon gas. Negligible amounts of electrode material are consumed during an operating time of several minutes. Under normal operating conditions 50% to 90% of the input electric power is transferred directly to the gas. The remaining power is absorbed by the water-cooled electrodes. Measurements were made to determine the total gas enthalpy and the proportion of the enthalpy in directed kinetic energy, random particle motion, and ionization energy. From these measurements it is postulated that the gas is initially in a non-equilibrium state on leaving the arc, but approaches equilibrium relatively quickly when confined to a constant diameter jet outside the arc. The gas temperature range in these experiments varies from 5000°K to 15000°K.