Full Details

Name and Model Number Keuffel & Esser 4139
Cooke Radio SR
Country of Origin USA
Date of Manufacture 1943 Catalog - World war II era
Front Scales LC A B T ST S D DI
Back Scales L DF CF CI C D 2 pi
Scale Length 25 cm (10 inches)
Type of Rule Slide Rule
Construction Celluloid on Mahogany, metal framed cursor , adjustable end frames.
Area of Use Generic
Comment Radio calculations believed during and after WWII. Note the rare circular Keuffel & Esser logo.
Rarity RR
Donor Collection of Clay Castleberry
Match Number 299
(Click Picture for Details)

In conjunction with our 'donors' we assign a rarity rating to each item, based on the system devised by Herman van Herwijnen
(1929 - 2004), renowned Dutch collector, author, and creator of Herman's Archive, a collection of 5,000 slide rule images on CD.
• RR = Rare - 1 of 25 collectors has one; it may take a year to find an example in the marketplace.
• RRR = Very Rare - only a few known to collectors; may be several years before it comes up for sale.
• RRRR = Extremely Rare - a museum piece; unlikely that an example will come up for sale.