Full Details

Name and Model Number Wilson's Cylindrical Calculator
for Rule Work
Country of Origin USA
Date of Manufacture c. October 1915
Front Scales Paper cylinders with font sizes
Back Scales None
Scale Length 20 cm (8 inches)
Type of Rule Cylinder
Construction Wood case with glass cover, paper cylinders
Area of Use Generic
Comment "Wilson's Cylindrical Calculator for Rule Work" was probably used in the printing industry to help with spacing and layout.
Rarity RRR
Donor Collection of Lou Gotlib
Match Number 302
(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.