Moth-Ball Puzzle as Window-Advertising Novelty
A druggist recently puzzled thousands with a novel window display. A small white ball in a 1-in. glass tube, about 10 in. long, displayed in a show window, would sink to the bottom, then slowly ascend, only to sink as before. A sign reading “What Makes It Move?” kept the crowd guessing. The tube was apparently filled with water. The construction is simple. The tube is about three-quarters full of carbonated soda water. The white ball is an ordinary moth ball. The ball sinks, and when it becomes soaked gradually as it lowers, bubbles of gas cling to it, carrying it to the top of the solution. There the gas escapes, destroying the ball’s buoyancy, and causing it to sink again, This process is repeated over and over.—David J. Lonergan, Minneapolis, Minnesota.