Full Details

Name and Model Number Tavernier-Gravet 43 R
Country of Origin France
Date of Manufacture 1921?
Front Scales A[B S C]D
Back Scales ? + partial B T B
Scale Length 25 cm
Type of Rule Slide Rule
Construction Celluloid on wood
Area of Use Electrical
Comment Notice that the scales are not named according to the usual system adopted later by almost all major makers.

It is not easy to determine which is the front or back face of the slide. One of its faces bears —on the same rim— a peculiar scale going from 100 to 60 and a partial B scale with a KW (kilowatt) gauge mark engraved at 843. The L scale is on the brim of the rule, which bears also gauge marks to calculate the resistance, the weight and the volume of cylindrical wires. The model number is stamped on the ends of the slide and the body.
Rarity RR-RRR
Donor Photo from a collection in Belgium
Match Number 358
(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.