The idea of rotation, associated with calendar signs and periods, finds its most striking and convincing exemplification in the following description of the ancient Mexican game “of those who fly,” translated from Clavigero (op. et ed. cit. p. 236). This performance, which furnished a diversion to the Spaniards after the Conquest, had evidently been, originally, connected with religious ideas. “The Indians selected a tall, stout and straight tree, and, lopping off its branches, planted it firmly in the centre of the great square” (which was always situated in the centre of the city and had four roads leading to it from the four quarters). “On the summit they placed a large cylinder of wood, the shape of which was compared by the Spaniards to that of a mortar. Four strong ropes hung from this and supported a square frame composed of four wooden beams. Four other ropes were fastened by one end to the pole itself and wound around it thirteen times. Their loose ends were passed through holes in the middle of each beam and hung from these. Four Indians, masked as eagles or other birds, ascended the pole singly, by means of certain loops of cord, and mounting on the cylinder they performed in this perilous position a few dance-like movements. Each man then attached himself to the loose end of one of the hanging ropes, and then, with a violent jerk and at the same moment, the four men cast themselves into space from their positions on the beams. This simultaneous movement caused the frame and cylinder to revolve and uncoil the ropes to which the men were fastened and these descended to the ground after performing a series of widening circles in the air. Meanwhile a fifth individual, who had mounted the wooden cylinder after the others, stood on this as it revolved, beating a small drum with one hand, whilst he held a banner aloft with the other.” Whilst it is obvious that this peculiar and dangerous performance clearly symbolized axial rotation, typified by the revolving pivot and the four men in aërial motion, its full meaning and intention are only made clear by the following explanation recorded by Clavigero. “The essential point in this game was to calculate so exactly the height of the pole and the length of the ropes, that the men should describe precisely thirteen circles each before reaching the ground, so as to represent the cycle (of 4×13=)52 years.” This passage constitutes absolute proof that the Mexican Calendar system was intimately associated with axial rotation and ideas such as could only have been derived from observation of Polaris and of the circumpolar constellations. The game itself was a beautiful and well-conceived illustration of the flight of time, typified by the aërial circles performed by the men masked as birds, and of its methodical division into fixed periods.