| Name and Model Number | Schauer Mechanical Pencil Slide Rule |
| Country of Origin | Germany |
| Date of Manufacture | Late 1920s |
| Front Scales | Marked: Ho, o, u Hu, T, L, & S (equivalent to the A, B, C, D, T, L & S scales) |
| Back Scales | none |
| Scale Length | 10 cm |
| Type of Rule | Other |
| Construction | 15-cm long metal (nickel alloy ?) mechanical pencil with sliding sleeve and cursor. |
| Area of Use | Generic |
| Comment | Celluloid cursor window is built into pocket clip. Patented in 1926 by Joachim Schauer of Lwow, Poland.
Marked with advertising for J.M. Voith, Maschinenfabrik, Heidenheim, Germany. |
| Rarity | RRR |
| Donor | Collection of Ed Chamberlain, USA |
| Match Number | 173 |
| 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. |