ID: 
2307
Maker's Name: 
Noris Chromo
Where made: 
Germany
Dimensions: 
1.2 × 1.2 × 25 cm

Carbon arcs were run on DC supplies, around 45 to 60 Volts minimum. The rod with a tip crater was used as the positive electrode. In operation it erodes and deposits some carbon on the negative electrode to form a cone. The negative electrode was often copper-plated to reduce the resistance of the rod.