Introduction to the Compass Cart and the Jiligu Cart: The Compass Cart was invented by the Yellow Emperor himself, and the Jiligu Cart was invented by the Yellow Emperor’s minister Jiutian Xuannv. The reliefs show the inventions and achievements of the "Guide Car" and the "Jiligu Car". The direction of the driver's finger on the compass car will not change no matter how the car body is moved or operated. The Ji-Li Drum Cart is a track-recording car used in ancient China to calculate road mileage. There is a wooden man holding a hammer to beat the drum inside the car. Each mile is hit by a hammer, hence the name Ji-Li Drum Car.