|Name and Model Number||Keuffel & Esser 4018 |
|Country of Origin||USA|
|Date of Manufacture||1909|
|Front Scales||C, N^2 (2 circles)|
|Back Scales||Tan, Log, Sine (2 circles)|
|Scale Length||5" (front scale)|
|Type of Rule||Watch Type|
|Construction||Metal with glass windows|
|Area of Use||Generic|
|Comment||Metal case with glass front and back.
Large stem wheel turns moveable front metal scale disks.
Small stem wheel turns moveable front and back cursors; fixed cursors on glass front.
Patent Appl. For, fob loop at 7 o'clock, Serial No. 869.
|Donor||Collection of Dr. Paul J. Tarantolo Jr.|
(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.|