Up for bids is a vintage 1931-1937 USSR Slide Rule 25cm Latvian "Prometei" Prometheus Engineering Rare

Incredible history. In great condition. 

From the internet: "Prometei (Прометей) was by far the most popular soviet slide rule brand during 1930's. 

Prometei rules were produced from ca. 1930 to 1937 by Latvian cultural-educational society Prometejs (Просветительное общество Прометей). 

Besides names Prometei and Prometejs also Prometheus could be used, because of the English text of the case.

Prometejs society existed 1924-1937 and the most important part of it was its publishing department in Moscow. Prometei slide rules were produced in Leningrad.  

The society was shut down 14.7.1937 by a decree of the USSR Council of People’s Commissars.  All functionaries and many of the members (for example well-known artist Gustavs Klucis) were killed as nationalists or enemies of the people. The property of the society was confiscated, but the production of slide rules continued with a different name."

Please feel free to email with questions I combine shipping. Thank you.