Full Details


Name and Model Number Keuffel & Esser 4095
Merchantsí Slide Rule
Country of Origin USA
Date of Manufacture c. 1915
Front Scales DF [CF C ] D
Back Scales D [CI]
Scale Length 25 cm
Type of Rule Slide Rule
Construction Duplex mahogany body with celluloid laminate scale surfaces. Early frameless cursor with metal blocks.
Area of Use Other
Comment For business use.
This rule was the first release of the 4095 family of rules that would later become the 4095-3.
Rarity RRR
Donor Collection of Clark McCoy
Match Number 205
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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.