A jowler bin was a rubbish bin, tho I don't know the derivation of the word. I used to sing this song but I could never understand how the dolls worked until I saw someone with a set of them once. The dolls were wooden with loose joints at the hips and knees, and a wooden rod attached to the back of the body, which the operator held. He sat with a piece of wood about 2-3 inches wide, and about 18 inches long, tucked under his thigh. The doll was held so that its feet just rested on the far end of the plank, and he tapped the plank just behind the doll, making the plank bounce up and down slightly, so that the doll's feet bouced up and down in time, creating the illusion that the doll was dancing.