Full Details

Name and Model Number Rapidus
Country of Origin Probably Germany or Austria
Date of Manufacture Unknown
Front Scales K A [ B CI C ] D L
Back Scales  
Scale Length 12.5 cm
Type of Rule Slide Rule
Construction Paper glued on wood
Area of Use Generic
Comment Cheap model probably produced during, or just after, WWII.
Rarity RRR
Donor Photo from a collection in Belgium
Match Number 332
(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.