The $ 1 . 40 stamp shows the ancient compass as a south - pointing ladle . the stamp depicts a hodometer developed from a compass cart and a ship launched by zheng he ( ad 1371 - 1433 ) , a world - renowned navigator , during his epoch - making expeditions 背景绘画记里鼓车以及明朝三宝太监郑和（ 1371 - 1433年）下西洋所乘船舰。前者在指南车的基础上发展而来，后者远洋航行，依赖的是导向的指南针。
