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Keuffel and Esser Model 4058W Beginner's Slide Rule

• Type: Closed Body Enhanced Mannheim
• Size: 10 Inches / 25 cm
• Material: Pine and ink
• Scales:
  • Front: A [ B C ] D
  • Back: [ S L T ]
• HvH: 1524

Manufactured between 1938 (patent date on cursor) and 1943 (after which K&E added CI and K scales.) If the cursor is a replacement, the rule could have been made as early as 1936. A slight color difference between body and slide could indicate the slide was from a different rule. But since quality control wasn't an issue with this model we can probably accept that the rule is now as it started.

This rule is intended to get a student's feet wet without forcing him to the expense of a professional rule. If the student advanced in mathematics, he might have been encouraged (or peer-pressured) into springing for a "real" slide rule.

With black paper box.