Lot Essay
The time is shown when, using the compass to point northwards, the shadow of the perpendicular openwork arm is cast on the dial.
Compare with two similar compass-sundials illustrated in The Complete Collection of the Treasures of the Palace Museum - Scientific and Technical Instruments of the Qing Dynasty, 1998, p.25, no.18 and p.27, no.20
Compare with two similar compass-sundials illustrated in The Complete Collection of the Treasures of the Palace Museum - Scientific and Technical Instruments of the Qing Dynasty, 1998, p.25, no.18 and p.27, no.20