《鲁班经》之“围棋盘式” "Luban Sutra" of the "WeiQi Board Style"
https://zhuanlan.zhihu.com/p/654179542
......
The radius of the board is 1 foot 5 inches(Chinese size), which alludes to the concept of "the center of the earth" when the summer solstice shadow is 1 foot 5 inches long.
That is to say, on the summer solstice in Songshan, Henan Province, "the center of the earth" of the Zhou Dynasty, the Pole for measurement of the summer solstice shadow is set up in the center of the board, the pole is 8 feet long, and the shadow of sun is 1 foot 5 inches long, which is exactly equal to the radius of the traditional board (inscribed circle). This is where the traditional board originated as an ancient astronomical tool.
For details, see: Collection of Studies on the Origin of WeiQi and Ancient Chinese Astronomy and "Zhou Bi" at https://zhuanlan.zhihu.com/p/648778697
......
The ancient name of the center point of board is "Zhong", Chinese 中。
Zhong Guo 中国 means China.
Attachment:
111.jpg [ 31.14 KiB | Viewed 6545 times ]