Full Details

Name and Model Number Keuffel & Esser 4095-1
Merchantsí Slide Rule
Country of Origin USA
Date of Manufacture c. 1925 based on serial number
Front Scales DF [CF C ] D
Back Scales D [CI]
Scale Length 12.5 cm
Type of Rule Slide Rule
Construction Duplex mahogany body with celluloid laminate scale surfaces.
Area of Use Other
Comment For business use.
This rule is rarely seen.
Rarity RRR
Donor Collection of Clark McCoy
Match Number 203
(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.