A Gavel pivoted between two blocks on a large board is displayed. The gavel is shown to swivel freely, and drops under its own weight. The performer can cause it to rise, and knock in a ghostly fashion, to answer questions, do simple mathematics, or act as a lie detector etc.
The gavel is completely under performers control at all times. This is a clever mechanical prop, made in wood, that can be used under all performing conditions.
