| Name and Model Number | Otis King Calculator Model N Carbic Ltd. |
| Country of Origin | England, London |
| Date of Manufacture | 1923 |
| Front Scales | Scale No. 424: Sterling Currency - 1/4d. to £1,000 |
| Back Scales | Scale No. 422: Numbers, vulgar fractions. French & English Weights & Measures - 1/4 to 2,500 |
| Scale Length | 168 cm |
| Type of Rule | Cylinder |
| Construction | Nickel plated brass with paper scales. Scales printed in spiral fashion around the upper cylinder and lower handle. |
| Area of Use | Generic |
| Comment | For currency calculations. |
| Rarity | RR |
| Donor | Collection of Dr. Paul J. Tarantolo Jr. |
| Match Number | 217 |
| 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. |