FINE ACQUISITION FOR COLLECTORS !!!

Circular Slide Rule SPUTNIK (travelling companion - in Rusian) -
Made of plastic on the "Kalibr" (Calibre) factory (plant) in Moscow in 196x-1970x

RAREST USSR (now-Russia) CIRCULAR SLIDE RULE
Intended for performance of  most often occurs mathematical operations:
* multiplication
* division
* erection in a square
* extraction of a square root
* finding of trigonometrical functions of a sine and tangent
* calculation of the area of a circle.
 
"Sputnik" slide rule has two working sides -
on each of which are located large and small rotating dials and transparent
rotating disk with the line - pointer.
Diameter 72mm (2.75 inches) - all approxxx..