Full Details

Name and Model Number Keuffel & Esser "American"
Country of Origin USA
Date of Manufacture Pre 1900
Front Scales A [B C ] D
Back Scales S L T
Scale Length 25 cm
Type of Rule Slide Rule
Construction Mannheim boxwood body with celluloid laminate scale surfaces. The frame is solid and not adjustable like rules after 1900.
Area of Use Generic
Comment This rule does not appear in the catalogs. It is theorized that this was the first slide rule actually produced by K&E in the USA. It is very similar to the later model # 4054. The only thing that identifies this rule is the name on the case
Rarity RRR
Donor Collection of Clark McCoy
Match Number 218
(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.