Astronomical Instruments of the Imperial Observatory

A woodblock illustration depicting two types of drafting or surveying compasses (dividers) set against a stylized landscape background. The top instrument is a large pair of dividers with a circular spring-head and a curved adjustment arc (wing) passing through the legs, secured by a screw. It stands on a textured ground representing a small hill or mound with sparse vegetation. The bottom instrument is a smaller pair of dividers with a flat, circular hinge and a straight threaded adjustment rod with a wing nut. The entire illustration is enclosed within a double-line rectangular border.

Figure 50