The performer reads the minds of the spectators and discovers which one of several match folders was selected behind his back

Collect several match folders bearing different designs and place them on a table.

"I have discovered something" you say, "which will put the telephone company out of business. I have found out how to know what people are thinking before they tell me. Let's try it. When my back is turned I want someone to select one of these match folders, open it, tear out a match, close the folder, and put it back with the others."

Turn your back until this is done.

"Now, I am going to hold each folder to my forehead and concentrate. When I am holding the selected folder I want you all to think, 'That's it!9 just as hard as you can!'

You do this and find the selected folder. The method is extremely simple. At the beginning, as you collect and set out the folders, you push the flap of each folder down tightly behind the sandpaper strip. When the spectator opens a folder, tears out a match, and recloses the folder, he never pushes the flap in firmly. This is your clue. When you pick up each folder, hold it between thumb and forefinger, the thumb on the flap. Push the flap toward the sandpaper strip. The folder whose flap moves slightly is the one that was selected.

The trick seems even more like real mind reading if you keep your eyes closed throughout, or, better still, do it blindfolded.