Give a person two half-crowns and request him to hold them horizontally
between the tips of his thumb and finger of his right hand, the coins
touching each other. Then request him to drop the lower coin in his left
hand and you will tell him which side will come uppermost. First note
which side of the coin is underneath when you place them in position,
for that will be the uppermost side when it reaches his left hand. The
lower coin will turn completely over in the act of falling: nothing can
prevent it. The distance between the hands should be from fourteen to
sixteen inches.