Chinese sun and moon mirrors
The yángsuì 陽燧 or sun-mirror was an ancient Chinese burning-mirror that concentrates sunlight to ignite tinder and the fāngzhū 方諸 or moon-mirror was a device that collects nighttime dew by condensation. These two bronze implements are literary metaphors for yin and yang, associating the "yang-mirror" yangsui with the sun (a.k.a. tàiyáng "great yang"), fire, dry, and round, and the "yin-mirror" fangshu with the moon (tàiyīn "great yin"), water, wet, and square.
There are numerous Chinese names for the fire-producing yángsuì 陽燧 "sun-mirror" and water-producing fāngzhū 方諸 "moon-mirror".
Yángsuì < Old Chinese *laŋsə-lu[t]-s can be written 陽遂 or 陽燧, compounding yáng (of yīnyáng) "sunshine; shining; sunny side" with suì "advance; accomplish; achieve" or suì (clarified with the fire radical ) "light a fire". Compare the mirrorless sui terms Suiren 燧人 (with "person") "a mythical sage who invented friction firelighting", suìshí 燧石 (with "stone") "flint", mùsuì 木燧 (with "wood"), meaning either "hearth-board" or "fire-drill", and fēngsuì 烽燧 (with "beacon") "beacon-fire". Yángsuìzú 陽燧足 "sun-mirror feet" is an old Chinese name for "brittle star". Suì 燧 also had early graphic variants 鐆 and 䥙, written with the metal radical 金 specifying the bronze mirror.
The Hanyu Da Cidian unabridged Chinese dictionary (1993, 11: 1974) gives three meanings for yángsuì 陽遂 (written without the "fire radical"): 亦作"阳燧" 古代利用日光取火的凹面铜镜 ["Also written 阳燧, a concave bronze mirror anciently used to start a fire from sunlight."]; 清畅通达貌 ["appearance of clear, unobstructed flowing"], which was first recorded in a poem (洞箫赋) by Wang Bao (c. 84 – c. 53 BCE); and 古代车上的一种采光装置 ["an ancient type of chariot window that admits light"], which was first recorded in the Book of Jin history covering 265 to 420 CE.
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