| Name and Model Number | Anderson, Casella Improved Long Scale |
| Country of Origin | England |
| Date of Manufacture | 1910-20 |
| Front Scales | Special 4 & 8 segment extended scales |
| Back Scales | None |
| Scale Length | 1.2-m |
| Type of Rule | Slide Rule |
| Construction | Closed frame rosewood body with celluloid laminate scale surfaces. Dimensions: 36.4-cm x 4.9-cm. Slide has celluloid wings with scale labels and mnemonics at both ends to facilitate calculations . Metal-framed glass cursor also has scale labels. British Patents for the segmented scale granted on Apr. 22, 1903 and Aug. 30, 1904 to a Lt-Col. Anderson. Casella & Co. was the exclusive dealer for this slide rule. It had a short life from 1904 to about 1910. |
| Area of Use | Generic |
| Comment | British Patents for the segmented scale granted on Apr. 22, 1903 and Aug. 30, 1904 to a Lt-Col. Anderson. Casella & Co. was the maker and exclusive dealer for this slide rule. It had a short life from 1904 to 1910. The red color of some labels and the model identification are faded due to light exposure. Cardboard slip case for storage. |
| Rarity | RR |
| Donor | Collection of Ed Chamberlain |
| Match Number | 138 |
| 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. |