Astronomical Instruments of the Imperial Observatory

A technical woodcut illustration depicts two tall, rectangular pillars or towers marked with grid lines and scales. Between the pillars, a plumb line, which is a rope with a weighted bob at the bottom, hangs vertically. The pillars are labeled with the celestial stem character Jia. To the left, a decorative architectural element or part of a machine frame is visible. The background shows a stylized landscape with hills. A vertical inscription identifies the figure number.

Figure Forty-Six

Jia

Jia

Yi