Faber Castell 1/48 Winkel Machine time slide rule 1940 Germany

This is an early wooden Faber Castell slide rule for the craftsman of its days, working heavy machinery. Made in Germany, in the German language. Made to the needs of a special group of workers using a system invented by Dr. Winkel (design registered in 1920). This model is 1/48 “Maschinenzeit” which is German for machine time which was being produced under this number since 1939 (earlier 348) the name was not used yet, just reference to the system by Dr. Winkel. Made still with wooden pegs holding the laminate so probably in the 1940’s. It has many different calculations and a whole different layout, many words and symbols compared to a mathematical slide rule. The table on the back is also in German with clearly visible red and green ink to complement the black. The slide rule uses both black and red ink. The glass cursor has a small kW marked hairline and a long PS marked hairline on the thick aluminum rim. Everything is in great and complete condition with only small signs of use and age only. Both part of the container are complete, no tears and  correctly signed with 1/48 and system Dr. Winkel 1/48 as is the slide rule itself. It measures ca. 30 cm or ca. 12 inches. Check the attached video on how to work your vintage man tool : slide rule operation instructions!