| Name and Model Number | Thomas Bradburn |
| Country of Origin | UK |
| Date of Manufacture | c1850 |
| Front Scales | A/B, B/C |
| Back Scales | None |
| Scale Length | 12" |
| Type of Rule | Other |
| Construction | Ivory/German silver |
| Area of Use | Generic |
| Comment | Routledge two foot folding rule with slide rule |
| Rarity | RRRR |
| Donor | Collection of Colin Barnes |
| Match Number | 78 |
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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. |