Full Details

Name and Model Number Keuffel & Esser 4035
Country of Origin USA
Date of Manufacture 1901-1927
Front Scales A B C D
Back Scales S L T located on back of slider
Scale Length 20 cm (8 in)
Type of Rule Slide Rule
Construction Celluloid on mahogany -frameless cursor and adjustable frame
Area of Use Generic
Comment Early 8 inch model of the 4041 family of slide rules
Rarity RR
Donor Collection of Clay Castleberry
Match Number 321
(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.