Astronomical Instruments of the Imperial Observatory

A large-scale scientific or architectural diagram within a double-line border is presented. The upper portion features a large semicircular instrument, likely a quadrant or surveying level, mounted on a tripod-like wooden frame. The instrument has a graduated scale along its curved edge. A plumb line with a circular weight hangs from the central pivot point, labeled Wu. Various celestial stem and earthly branch characters are used as labels on the components: Wu at the top pivot, Geng on the left supporting arm, Ren on the inner horizontal bar of the semicircle, Xin at the base of the left leg, and Ji near the plumb bob. The instrument sits on a flat, segmented base or platform. The lower portion of the image depicts a rectangular structure, possibly a wall or a foundation, with a complex internal lattice or truss pattern consisting of intersecting diagonal lines. A decorative, curved architectural element sits atop this structure. The background suggests a landscape with horizontal lines representing water or flat ground.