| Name and Model Number | System Tombeur, Basic - Prototype |
| Country of Origin | England |
| Date of Manufacture | 2012 |
| Front Scales | A [C] § |
| Back Scales | None |
| Scale Length | 244 mm |
| Type of Rule | Slide Rule |
| Construction | Mahogany, Paper, Perspex |
| Area of Use | Other |
| Comment | Handmade forerunner of System Tombeur Basic slide rules for jugglers.
Designed and made by Colin Tombeur. |
| Rarity | RRRR |
| Donor | Collection of Colin Tombeur |
| Match Number | 75 |
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| RR | = Rare -- 1 of 25 collectors has one; it may take a year to find an example in the marketplace. |
| RRR | = Very rare -- only very few known to collectors; may take several years before one comes up for sale. |
| RRRR | = Extremely rare -- a museum piece; unlikely that an example will ever come up for sale. |