This white plastic German slide rule has a clear plastic cursor. Scales 25 cm. long are on the front of the base of the rule and on both sides of the slide. The slides on the rule are K, A, B, P, S, and T. Those on the slide are B, BI, CI and C on the front and LL1, LL2, and LL3 on the back. The beveled top edge has a scale of equal parts divided to tenths of a centimeter, 27 centimeters long. The front of the instrument has an L scale. The back has a set of tables of use in mathematics, mechanics, and electronics.
The scale fits in a plastic case that is transparent on top and green on the bottom. Also included is a manual by Faber-Castell entitled "Anleitung Castell Praezisions-Rechenstaebe fuer Maschinen und Elektro-Ingenieure." This manual describes the Castell models 1/54, 4/54, 67/54 b, 67/54 R, 111/54, and 111/54 A. The only three of these with scales 25 cm. long are the 1/54, the 111/54, and the 111/54 A. None of the rules described in the booklet has a BI scale.
Our collection database is a work in progress. We may update this record based on further research and review. Learn more about our approach to sharing our collection online.
If you would like to know how you can use content on this page, see the Smithsonian's Terms of Use. If you need to request an image for publication or other use, please visit Rights and Reproductions.