1967 20" long slide rule soviet Engineering vintage big Extended Length For Sale

1967
USSR
vintage slide rule 58 cm long material- wood, plastic. sight window - nickel plated steel A Soviet engineering slide rule 58 cm long was used for precise engineering calculations, the peculiarity of this ruler is that it is in very good condition. Judging by the absence of any minimal defects, this slide rule has not been used by anyone; the case has traces of long storage. A collector who is thinking about buying this rare slide rule may have a question: why is the sight window not as wide as on the slide rule presented in the museum and shown in the photo from the film. I explain that these rulers were produced with sight windows of different sizes in width in different years . The size of this window is such that it will not fit on any other Soviet slide rule, only this one. These slide rules were not sold in public stores but were received on orders from research institutes, factories, laboratories, etc.in the last photo in the description is a still from the Soviet documentary "Test of a clean hydrogen bomb with a yield of 50 megatons"