| Name and Model Number | Tavernier-Gravet (?) Machinist's Slide Rule |
| Country of Origin | France |
| Date of Manufacture | c. 1920s ? |
| Front Scales | Special scales for efficient milling |
| Back Scales | Advertising for The Acme Co, Cleveland, Ohio & Windsor, Vermont |
| Scale Length | 20 cm |
| Type of Rule | Slide Rule |
| Construction | Celluloid on boxwood with beveled edge, 3.8 cm x 23 cm |
| Area of Use | Other |
| Comment | Marked "Made in France", but not marked Tavernier-Gravet. Slot cuts in ends of lower stator are characteristic of only Tavernier-Gravet slide rules. The scales may have been patterned after the Speed & Feed slide rules made by Carl Barth in the US in the early 1900s. Windsor, Vermont is an old mill Town 30 miles south of my home. It was famous for its machine tool industry. The Acme Co. was the maker of the first commercially successful automatic multiple-spindle screw-manufacturing machine. I conclude that the Acme Co. contracted with Tavernier-Gravet to produce this slide rule.
This is the only example known to me. |
| Rarity | RRRR |
| Donor | Collection of Ed Chamberlain |
| Match Number | 194 |
| Thumbnail (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. |