Full Details

Name and Model Number Keuffel & Esser 4065T
with Column Cursor
Country of Origin USA
Date of Manufacture c. 1915
Front Scales A [B S C] D
Back Scales A [BI T CI] D L
Scale Length 20 cm
Type of Rule Slide Rule
Construction Celluloid scale surfaces on mahogany, duplex slide rule, with "column" framed glass cursor.
Area of Use Generic
Comment This example has "decimal keeping" mnemonics and the owner's name neatly engraved on the front.
The mnemonics assist the user in keeping track of the position of the decimal point.
This is especially valuable for problems with multiple operations.
Rarity RRRR
Donor Collection of Ed Chamberlain, USA
Match Number 136
(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.