Note 105 — Chapter XI · HOME MADE MUSICAL INSTRUMENTS
Reading edition
If you will look closely at the spinning coin you will see that when it spins fast at first the axis about which it rotates is its diameter and that the coin stands upright. As the coin commences to die down the axis about which it spins gradually begins to shift from the diameter to the center of the coin until finally at the finish the coin is spinning directly about its center. This motion is the same as the processional motion of the earth.