Full Details

Name and Model Number Keuffel & Esser 4095 Special
Merchantsí Slide Rule
Country of Origin USA
Date of Manufacture c. 1934 based on serial number
Front Scales DF [CF C ] D Scales have special markings for percentage markup calculations.
Back Scales D [CI]
Scale Length 25 cm
Type of Rule Slide Rule
Construction Duplex mahogany body with celluloid laminate scale surfaces. The scales on the front side of the rule have special markings for percentage markup calculations. This rule appears to have a replacement cursor from a later time.
Area of Use Other
Comment For business use.
This rule does not appear in K&E catalogs.
Rarity RRR
Donor Collection of Clark McCoy
Match Number 204
(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.