Wichmann Artillery Arc bombing slide rule 1930 Germany

This is an early slide rule produced for the German Army (later edition were marked GWR like this model). It measures the arc for bombing (Geratekonstante and Winkelsekunde). It comes in the original black cardboard case, both rule and case are marked Wichmann, who was one of the contractors for making this specific slide rule. Guestimating it is from the late 1930’s. Everything is complete, clean and in working condition with only small signs of use and age. Unique large cursor with instructions in German on the back. It measures 38 cm or 15 inches wide. Check the attached video on how to work your vintage man tool : slide rule operation instructions!