How did the water transport instrument in Song Dynasty work?

This water transport instrument made in the Song Dynasty has an armillary sphere on the upper floor to observe the positions of the sun, the moon and the stars. In order to facilitate observation, it is covered with nine movable roof panels, which have the same function as the retractable spherical platform roof on the modern observatory. In the middle layer, an imager is placed at the star position of a spherical celestial body, and the imager is a sphere; There is a mechanical device that can make the constellation rotate from east to west, consistent with the apparent motion of celestial bodies, and make the position of spherical constellation consistent with the astronomical phenomena. There is a wooden pavilion on the lower floor, which is divided into five floors. There is a door on each floor, and at some point, Woodenhead will come out to strike the time. Behind the wooden pavilion, a leaky kettle and a mechanical system were installed. The leaky kettle can make the water rise and fall, turn the wheel and make the whole instrument move step by step. Very clever, let a person sigh.

The power device of this hydraulic observatory is equivalent to the clock mechanism on modern telescopes, which can keep the stars running in the sky in view.