| Name and Model Number | Barth, Carl Complete Machinist Lathe Slide Rule |
| Country of Origin | USA |
| Date of Manufacture | 1926 |
| Front Scales | Special scales for efficient turning of iron on a lathe |
| Back Scales | NONE |
| Scale Length | |
| Type of Rule | Slide Rule |
| Construction | Varnished paper scales on heavy mahogany. 50.8-cm x 19.0-cm; 4 exchangable slides and one exchangable insert for using this slide rule for other metals. |
| Area of Use | Technical |
| Comment | Carl Barth promoted Frederick Taylor's "Scientific Management" theories in the machine shop workplace; made to order for G.E. Schultz. Dated Feb. 12, 1926. Carl Barth signed this slide rule. Barth was a consultant to the machine tool industry from about 1900 to 1928. This is one of his last designs and may be one of a kind. |
| Rarity | RRRR |
| Donor | Collection of Ed Chamberlain |
| Match Number | 124 |
| 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. |