Faber Castell 342 Columbus Rohrberg slide rule 1940 Germany

This is an early wooden Faber Castell slide rule, marked A.W. Faber on the original cardboard case. On the case are also the number 342, the”columbus” type and the “syst. Rohrberg” designation as well as 2 patent numbers. So made to the needs of a special group of business traveling world wide, using a system invented by mr. Rohrberg. Made in Germany in the 1940’s (estimated on the materials used and naming). It has many different calculations for different currencies and length measurements for many different countries. The extra information on the back is in German. The metal and glass curser has a 4 hairlines. The slider in the middle is extra wide with brass construction points. Everything is in very good and complete condition with some signs of age only, little use marks. It measures ca. 38 cm or ca. 15 inches. Check the attached video on how to work your vintage man tool : slide rule operation instructions!