Kreiken Planisphere Astronimical star chart 1930 The Netherlands

This rotatable star chart was produced in the Netherlands according to Dr E.A. Kreiken and produced by W. Versluys from Amsterdam in the 1930’s. Prof. Dr. Kreiken (1896-1964) studied astronomy in Groningen (the Netherlands) 1923 and worked in Indonesia, he later became a Professor in Astrophysics at the Ankara University in Turkey and founded the Ankara University Observatory (commissioned in 1954). The chart is fully functioning but fragile and measures 27 x 27 cm or 11×11 inches. On the back instructions in Dutch (older spelling of words). It shows clear signs of use and age, the gold on the outer rims is faded making is hard to read but the star chart itself is clearly visible in all 360 degrees, selling this as a display piece (priced according to condition). Check the attached video on how to work this vintage man tool!