|Name and Model Number||Tavernier-Gravet |
Butterfat Slide Rule
|Country of Origin||France|
|Date of Manufacture||c. 1910|
|Front Scales||Extrait [ Beurre ] Densité|
|Scale Length||22 cm|
|Type of Rule||Slide Rule|
|Construction||Closed frame boxwood; 23 cm x 3.3 cm. Scales printed directly on wood surface.|
|Area of Use||Other|
|Comment||For the dairy industry to determine the butterfat content of milk.
Taverinier-Gravet printed on lower narrow edge.
Uncertain if any other examples are known.
|Donor||Collection of Ed Chamberlain|
(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.|