Hertz’s theories are interesting but what he loves most is building things, working with his hands, connecting his fingers to the engine of his mind. Werner repairs a neighbor’s sewing machine, the Children’s House grandfather clock. He builds a pulley system to wind laundry from the sunshine back indoors, and a simple alarm made from a battery, a bell, and wire so that Frau Elena will know if a toddler has wandered outside. He invents a machine to slice carrots: lift a lever, nineteen blades drop, and the carrot falls apart into twenty neat cylinders.
