Notes: "This is a Faber Castell 67/87 R, which is a 12.5 cm Rietz slide rule with a small Addiator permanently attached to the back. The Rietz layout was one of the “enhanced Mannheim” scale layouts invented in the late 1800s. In this case, it was invented by Max Rietz at Dennert & Pape, and proved to be extremely popular in Europe. This slide rule marries the Rietz slide rule design with a six-column Addiator yielding a pocket slide rule that is not limited to only multiplication, division, and trig, but can add and subtract too. This slide rule appears to have been a promotional giveaway from the China Textile Engineering Corp Ltd. in Hong Kong."
