Full Details

Name and Model Number Dr. Grunert's
Country of Origin Germany
Date of Manufacture c. 1910
Front Scales 12 sections repeated 4x horizontally & vertically
Back Scales none
Scale Length Approximately 2 m
Type of Rule Other
Construction Paper on wood
Area of Use Other
Comment For solving the Pythagoras theorem equation.

Rarity RRR
Donor Collection of Ed Chamberlain
Match Number 144
(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.