Chinese Needham Type-A Diptych

Late 19th to early 20th century wooden Chinese Diptych, Needham Type-A. Made for use at 40° latitude (Beijing). Featuring a wooden lunar volvelle and equatorial sun and moon dial. Age of moon; volvelle with pointer; double hours; petalled brass rivet with gnomon hole plugged.

Featured in the Adler Planetarium.

Featured in the Science Museum Group.

Dimensions: 6.0 cm. x 8.5 cm. x 2.5 cm.

Diameter (Compass): 2.0 cm.

Weight: 2.0 oz.