Full Details

Name and Model Number Keuffel & Esser 4031
Country of Origin USA
Date of Manufacture 1915
Front Scales A [ B C ] D
Back Scales [S L T]
Scale Length 12.5 cm
Type of Rule Slide Rule
Construction Manheim mahogany body with celluloid laminate scale surfaces.
Area of Use Generic
Comment This is a unique specimen of the 4031 variety. It has fine scale divisions, a magnifier with its case, and metal cursor blocks. The combination makes this a rare rule.
Rarity RRR
Donor Collection of Clark McCoy
Match Number 208
(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.