Full Details

Name and Model Number Calculigraphe Model F-C
Country of Origin France
Date of Manufacture before 1878
Front Scales L, N^3
Back Scales none
Scale Length 11.3 cm
Type of Rule Watch Type
Construction nickel or German silver
Area of Use Generic
Comment This is the model F-C with the castle logo rather than the opisometer on the more common model H-C.
There are fewer than 6 known in hands of collectors.
Rarity RRR
Donor Collection of Clay Castleberry
Match Number 251
(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.