Kraul has been in the same family for three generations, and each generation brought a different trade to it. Mara Kraul started the business in the 1920s on artistic embroidery and knitting. Her son Walter, a mathematics teacher at the Rudolf Steiner School in Munich,… began designing waterwheels and cable cars for children who had to build them before they would work. He took over in 1976. His son Christoph, a meteorologist and physicist, joined in 1989 and designs the experiment kits.