Diagrams of Chariot Construction, Volume 1

Page 2

The Record of TradesOriginal: Kao Gong Ji. As established, this is the primary technical source for the text. says: "The felloe segment is what provides a solid embrace." Si NongA title referring to the Han dynasty scholar Zheng Zhong, who provided influential commentaries on the rituals and technical texts of the Zhou dynasty. says that the word for felloe (ya) should be pronounced like the word for "stumbling." This is because the rimOriginal: wang (輞). While ya refers to the segments, wang refers to the assembled outer circular frame of the wheel. is not made of a single piece of wood; its curvature must be achieved through bendingOriginal: rou (揉/輮). This refers to the ancient technique of using heat and moisture to bend straight timber into arcs.. In the "Explication of the Trigrams" in the Book of Changes, the Kan hexagram is associated with "shaping and bending" for the making of bows and wheels; the Ji Jiu Pian primer also contains the character for "bent rim." These segments are joined, sometimes five to form a circle, or sometimes six though the classical texts do not explicitly state the exact number of pieces. At the points where they "embrace" and join together, there must be "male teeth" Tenons. that interlock to ensure stability. Because these joints resemble teeth, the component is called a ya The Chinese word ya (牙) literally means "tooth.". The ShuowenThe foundational Chinese dictionary Shuowen Jiezi. says: "The word ya refers to the teeth of a male, depicting the shape of upper and lower teeth interlocking." In the context of chariot felloes, the character for ya is written with the wood radical Changing 牙 to 枒.. The definition provided is: "The meeting point of the chariot's rim." Thus, ya was originally the name for the joint where the rim segments meet; by extension, the entire rim came to be called ya. The Record of Trades says: "Examine the tenons and mortises to ensure they are not uneven (ou)." The Shuowen defines ou as "teeth that do not meet properly," which serves as evidence for the "tooth" meaning of the felloe segments. Furthermore, the Zuo Zhuan states: "The cheekbones and the chariot-felloe rely on each other." The commentator Du Yu notes that the "chariot-felloe" refers to the wheel itself. These various references mutually clarify the meaning.

Regarding the measurements for the width and thickness of the felloes, there are records in the classic text that can be consulted. The Record of Trades states: "Divide the height of the wheel into six parts; use one part to determine the circumference of the felloe segment." Thus, the felloe's girth is one-sixth of the wheel's height.