An easy and effective mode of terminating a money trick is to pass the
marked coin into the center of a large ball of Berlin wool or worsted,
the whole of which has to be unwound before the coin can be reached.
The modus operandi, though perplexing to the uninitiated, is absurdly
simple when the secret is revealed. The only apparatus necessary over
and above the wool (of which you must have enough for a good-sized
ball), is a flat tin tube, three to four inches in length, and just
large enough to allow a quarter or half-dollar (whichever you intend
to use for the trick) to slip through it easily. You prepare for the
trick by winding the wool on one end of the tube, in such manner that
when the whole is wound in a ball, an inch or so of the tube may
project from it. This you place in your pocket, or anywhere out of
sight of the audience. You commence the trick by requesting some one
to mark a coin, which you forthwith exchange by one or the other of
the means already described, for a substitute of your own, and leave
the latter in the possession or in view of the spectators, while you
retire to fetch the ball of wool, or simply take it from your pocket.
Before producing it, you drop the genuine coin down the tube into the
center of the ball, and withdraw the tube giving the ball a squeeze to
remove all trace of an opening. You then bring it forward, and place
it in a glass goblet or tumbler, which you hand to a spectator to
hold. Taking the substitute coin, you announce that you will make it
pass invisibly into the very center of the ball of wool, which you
accordingly pretend to do, getting rid of it by means of one or other
of the "passes" already described. You then request a second spectator
to take the loose end of the wool, and to unwind the ball, which, when
he has done, the coin falls out into the goblet.

The only drawback to the trick is the tediousness of unwinding. To
obviate this, some performers use a wheel made for the purpose, which