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Keuffel and Esser Model 4080-3 Log Log Duplex Trig

• Type: Log Log Duplex
• Size: 10 Inches / 25 cm
• Material: Mahogany and celluloid
• Scales:
  • Front: L LL1 DF [ CF CIF CI C ] D LL3 LL2
  • Back: LL0 LL00 A [ B T ST S ] D DI K
• HvH: 4618

The 4080-3 first came out in 1937, apparently to replace the 4092-3 which had disappeared from the catalog by 1939. Unlike the latter, this rule includes the ST scale which seems to be the scale that separates the serious trig rules from the runners up.

This rule was apparently originally owned by Bernard Hurewitz who caused his name to be engraved into the upper stator. Was this a service available from the factory or from his dealer? Or did Mr. Hurewitz have a magic name stamper that he applied to all his goodies?

This rule came to me in pretty bad shape, with lots of green goo corrosion and marks on the cursor body that suggested being in the sun too long. The original cursor had depolymerized into dust, and has been replaced.

The serial number, 884399, suggests a manufacture date in late 1940.