Biao du shuo 表度說 [Explanation of the Gnomon]
Numerous woodcuts (some full-page & some half-page) in the text. 6, 3, 40 folding leaves. 8vo, old, possibly orig. wrappers (with several repairs, one of which touches but does not obscure the text), orig. block-printed label on upper cover, new stitching. [Beijing: 2nd Preface dated 1614].
First edition, and very rare, of this work on the gnomon, one of the first astronomical measuring instruments, and its uses in astronomy and surveying. This work is important in the history of astronomy as it states here for the first time in China the doctrine that “the earth is spherical” (di ben... More