| Name and Model Number | Nestler Präzision Model 27 Slide |
| Country of Origin | Germany |
| Date of Manufacture | c. 1920s |
| Front Scales | 1 to ˆ10 [1 to ˆ10 ˆ10 to 10 ] ˆ10 to 10 |
| Back Scales | Back of slide: Sin (2 sections) & Tan (2 sections) |
| Scale Length | 50 cm |
| Type of Rule | Slide Rule |
| Construction | Closed frame pearwood (28 cm x 3.7 cm) with celluloid laminate scale surfaces and beveled edge. Cursor has two index marks to read lower edge scales. Cursor has 3 hairlines. "Albert Nestler" stamped in well. |
| Area of Use | Generic |
| Comment | Lower beveled edge : Sin & 3 cycles log scale
Top square edge: inch scale. Made by Nestler starting in the early 1900s. Special sin & tan scales on back of slide and lower edge related to extended scales. "No.27 Präzision Albert Nestler A.G. D.R. Patent" printed on black case. This is an early rare version of a model produced for perhaps 60 years. 15/30-cm and 25/50-cm models also sold, but no examples are known to me. Only 7 hits on eBay in 12 years of survey. |
| Rarity | RRR |
| Donor | Collection of Ed Chamberlain |
| Match Number | 170 |
| 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. |