Cinema Classics: Electrostatics: Demonstrations. Helium balloons rubbed with silk repel each other. Plastic hanger rubbed with silk and placed between the previously rubbed (silk) balloons repels them. The silk cloth that had been used to rub the balloons is placed between them and they are attracted. Hairbrush charged on cat attracts a hanging banana. Charged hairbrush attracts a stream of water. Balloon rubbed on shirt sticks to wall. Charged cup attracts stream of water. Foil suspended in vacuum responds to charged rod outside. Boy scuffs shoes on carpet and produces spark at doorknob. Wimshurst machine produces sparks, then lightning is shown.