That Rings A Bell

Effect: A small bell rings of its own accord.

Secret: A small bell is on your table. Hold an opaque scarf in front of you, between your hands. In the top right corner of the scarf there is a small pin. Show the other side of the scarf by moving the right hand to the left and the left hand to the right. Do this a few times, then pin the scarf to your left shoulder. This leaves your right hand free to reach down and ring the bell. Immediately bring your hand back up to recover the scarf from your shoulder.