| Name and Model Number | Russian Artillery Slide Rule System Iorish |
| Country of Origin | Soviet Union |
| Date of Manufacture | 1939 (on the bottom well), serial number 18153 |
| Front Scales | Artillery scales and normal C/D scales |
| Back Scales | S, S&T, T |
| Scale Length | Variable lengths, length of the slide rule 24.5 cm |
| Type of Rule | Slide Rule |
| Construction | Celluloid on wood |
| Area of Use | Military |
| Comment | The slide rule was constructed by Yu. Iorish, who described it in the article "Iorish Yu: Artilleriiskaya logarifmicheskaya lineika, Artilleriiskii zhurnal, 1936, Nr. 2, p. 26-38". For example the length was determined so that the slide rule could be kept in the artillery officer's standardized map case. The original design was slightly different and can bee seen at page 8 of the article "Leipälä T.: Soviet Prometei slide rules 1931-1937, http://www.rechenschieber.org/BochumPrometeirevised2013.pdf. At the beginning the slide rule had only one cursor, but later it was equipped with two cursors. The wooden case has a spring at the bottom, so that the slide pops up when the lid is opened. When Prometejs society was shut down in 1937 and its assets were confiscated, the office equipment factory changed the name to SPAR and this slide rule has been produced there. The logo on the back of the rule shows the trust to which SPAR belonged. |
| Rarity | RRR |
| Donor | Collection of Timo Leipälä |
| Match Number | 396 |
| 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. |