| Name and Model Number | Noble’s single rule |
| Country of Origin | UK |
| Date of Manufacture | c1895 |
| Front Scales | Routledge variant |
| Back Scales | Engineering and steel measure |
| Scale Length | 11” |
| Type of Rule | Other |
| Construction | Boxwood & brass |
| Area of Use | Other |
| Comment | 2-foot, 2-fold rule used in engineering.
Noble’s single slide rule is perhaps even rarer than the double 2-foot, 2-fold slide rules, it has the usual Noble 5 – 50 ‘D’ scale, but carries steel plate tables on the reverse side. There is only one version of Noble’s single rule, but it is obviously a Noble designed variant as it is mentioned in passing in his instructions for the ‘Eureka’ slide rule which was published in several editions including after his death in about 1910. Despite carrying the statement “...made by James Noble” it also carries an Edward Preston Trade Mark. |
| Rarity | RRR |
| Donor | Collection of an English gentleman |
| Match Number | 53 |
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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. |