Siemens Schmelzstromspitze electricity slide rule 1960 Germany

This Siemens marked slide rule comes in the German language and has no makers mark. This special slide rule comes has a very large cursor, almost as long as the rule and there is no slider. So in this unusual design the cursor also functions as slider. It is specially intended for calculations for transformers, resistance , fase and currents, probably for Siemens engineers and for internal company use only. It is in great condition with only small signs of use and age. It measures 18,5 cm or 7 1/4 inches. Do check the video below on how to work your vintage man tool : slide rule operation instructions!