Sensation Comics #92

The Holliday Girls are privvy to viewing Diana's jewel case. Etta asks what a simple pebble is doing among such priceless gems, and is told the story of how that pebble saved the world. Mars, God of War, Lord Conquest and the Duke of Deception hatch a plan to scorch the Earth with a giant magnifying lens. Diana is captured and bound by her magic lasso. She is told to lift the lens and aim it at the Earth, but, in doing so, throws a pebble she had picked up at the hand of her binder and is released. It is then a small enough effort for her to destroy the lens.