The Earth, since has a bulging shape at equator, behaves as a top that, when we try to change the way of its rotaxion axis, describes in the air a double opposed cone with the vertexes on the point of the top. In a similar way, the Earth reacts to the stress of Moon and Sun, spinning clockwise its rotation axis and keeping the same costant axial tilt of 23.5 degrees. It follows that, in time, the earthly axis not will point at Pole Star, but, step by step at a different point in the sky; besides the equinoctial axis which on 21st March 2006 is Earth - Sun - Constellation of Pisces will change within ages into Earth - Sun - Constellation of Aquarius. As Aquarius precedes
Pisces along the ecliptic, we speak about Precession of the Equinox of Spring. Alike Autumn Equinox not will happen in Virgo but in Leo. The exhibit which gives the name to the exhibition, wich is consistig of five instruments, visualizes the earthly axis, the astronomical precession circus and the dates and the ecliptical plane with the Zodiac areas, Ofiucus included. Moreover it visualizes the Equinoxes line, and the precession angle. Equinoctial motion (nodes line) and its correlation with the precession motion are immediately evident with great clarity. A tight instrument which can be sold to the schools.