Astronomical Instruments of the Imperial Observatory

The page contains two diagrams. Top: Figure 57 displays a sphere resting on a surface with a graduated arc marked 'Jia'. Bottom: Figure 58 depicts an elaborate scientific instrument on a tripod stand, featuring a horizontal ring and a diagonal sighting arm, with labels 'Wu', 'Ji', and 'Geng'. A hand emerging from a cloud indicates the operation of the arm, next to a vertical scale.

Figure 57

Jia

Figure 58

Ji

Geng

Wu