arc moves freely and continuously up and down the gap length thereby not concentrating at any one point but rather distributing its energy over the entire electrode length area this is opposed to end to end prior art devices where the arc is made to concentrate therebetween the freedom of arc movement of the present invention also contributes to electrode life by developing a polishing action of the electrodes this is accomplished in that an arc tends to take place between the two shortest points therefore any high points along the electrodes are polished away and if any pitting starts to occur the arc avoid that pitting spot until the entire arc area is equally worn this polishing results in increased electrode life and decreased electrode wear in one embodiment a tungsten material forms a non conducting volatite oxide which sublimes away harmlessly onto the ceramic holder of the spark gap device 18 leaving the electrodes 18 a and 18 b clean and polished this oxide formation due to the aforementioned low operating temperature of the electrodes forms extremely slow which results in a relatively long electrode life also tungsten being one of the highest melting metals does not pit or melt very easily the two 2 percent thorium due to its radioactivity contributes to stabilizing the breakdown voltage related to the electrodes the overall effect of the present invention is to provide a reliable spark gap device which in turn provides for a reliable rapid restrike or starting circuit for a metal halide lamp thereby eliminating any planned preventive maintenance of spark gap replacements as discussed in the 34 background 34 section in the practice of the present invention a circuit arrangement having the spark gap device 18 with the.