| Name and Model Number | Vade Mecum Timber Slide Rule |
| Country of Origin | England |
| Date of Manufacture | c. 1900 |
| Front Scales | A [ B C ] D, /measuring scales 1/8", 1/4", 3/8" |
| Back Scales | E F [ G G/ H1 H2 H3 I ] J K |
| Scale Length | 11.2" |
| Type of Rule | Slide Rule |
| Construction | Boxwood with brass end braces |
| Area of Use | Other |
| Comment | For calculating the volume of timber in logs.
Designed by George Bousfield for the timber trade. Designed to be held vertically when used. |
| Rarity | RRR |
| Donor | Collection of Clay Castleberry |
| Match Number | 244 |
| 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. |