Notes: "The Mannheim style slide rule is considered the first “modern” slide rule. It borrowed heavily from the Soho slide rule design, but was the first widely used slide rule to require a cursor. Sadly, this one has lost its cursor somewhere along the way. This slide rule was made by Tavernier Gravet in France, which you can just barely make out, where it isn’t covered by the ink stains on the lower edge. The address is 19 Rue Mayet, Paris, which was the third of five addresses for T-G, and identifies this slide rule as being from 1881-1939. "