Full Details


Name and Model Number Russian Pilot's Slide Rule
NL-7
Country of Origin Soviet Union
Date of Manufacture 1937
Front Scales Different scales needed in aviation
Back Scales Different scales needed in aviation
Scale Length Scales of variable lengths, length of the slide rule 21 cm
Type of Rule Slide Rule
Construction Celluloid on wood
Area of Use Aviation
Comment The first version of Soviet pilot rule was originally designed by L. S. Popov in 1927 and the last version NL-10u was introduced as late as 1978. This NL-7 (Navigatsionnaya Linejka) was produced in Leningrad at Prometei factory of Latvian cultural-educational society Prometejs. As explained in the user handbook Nikol'skoi M.N. & Blinov V. Ya.: Aeronavigatsionnaya linejka, 1939, 88 p., which can be uploaded at http://www.amyat.narod.ru/theory/nl/nl.djvu , following operations can be performed: a) normal arithmetic and trigonometric calculations, b) navigational calculations, c) bombing calculations, d) photogrammetric calculations. See also Leipälä Timo: Soviet Prometei slide rules 1931–1937 at http://www.rechenschieber.org/BochumPrometeirevised2013.pdf and Kormashov V.A.: Navigatsionnaya schetnaya linejka NL-10, 1956, 100 p., the reprint of which can be bought from Amazon.
Rarity RR
Donor Collection of Timo Leipälä
Match Number 397
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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.