Full Details

Name and Model Number Keuffel & Esser 4056
Country of Origin USA
Date of Manufacture 1921
Front Scales 10in / A [ B C ] D | 26cm
Back Scales [ S L T ] & Conversion Table
Scale Length 25 cm
Type of Rule Slide Rule
Construction Polished boxwood with printed scales and metal framed glass indicator.
Area of Use Generic
Comment Early version of the 4056 Favorite slide rule discontinued around 1925.
<4056> printed in red on left end of slide.
Rarity RRR
Donor Collection of Dr. Paul J. Tarantolo Jr.
Match Number 209
(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.