Streckenzugtafel Siemens Artillery slide rule 1950 Germany

This is an early artillery device made just after Worldwar II by Siemens for the German Army. The earlier models still carry the  Siemens logo but after the war I think Siemens chose not to incorporate these anymore. I also sold a later model of this Streckenzugtafel made by Aristo. This one is mode completely of metal (the Aristo one is all plastic) and is considerably smaller. This one measures 25×25 cm or 10×10 inches (aristo version measures 37 x 37 com or 15 x 15 inches). This slide rule is to determine the North-South and East-West distances between 2 points. The white plastic table is for making the calculations in the field. Both come in the original carrying bag. I can not find any issue marks. It is completly working and in good condition with some signs of use and age. Check the attached video on how to work your vintage man tool : slide rule operation instructions!