This article approaches the pedagogical importance of uncovering the mystery involved in the apparent ascendant movement of a double cone. Initially presenting some historical details of the invention of such an instrument, we move onto the analysis of the very physical origin of that referred physical illusion. Some clarifying images are exhibited and the relationship between the motion of the points of contact between the cone and the ramp and the motion of its centre of mass is discussed. In the sequence, the mathematical relationship amongst the main angles involved in that situation is discussed. The text is concluded pointing out to the fact that even such a mathematization is not sufficient to account for all the complexity involved in that physical situation. Beyond the analysed questions rest some other issues even more complex than those to be considered pointing out to the stability problem and to the possible utility of the double cone.
