Wubei Zhi (Vol. 49)

Current towers original: 臺 tai, referring to the "enemy towers" or bastions described on the previous page. fail entirely to follow proper regulations and suffer from numerous flaws. Take the corner towers, for example, which should ideally be level and straight.

If we consider a northeast corner, one should build a tower a certain number of feet and inches original: 丈尺 zhang-chi. eastward along the northern wall, and likewise build a certain distance northward along the eastern wall. If one wishes to attach the tower to the wall to save labor, then if it is attached to the eastern wall, it should not be further attached to the northern wall; if it is attached to the northern wall, it should not be further attached to the eastern wall.

Even if it is attached to both walls, it must still function as a proper tower. For those where three sides are attached to the wall, the size is reduced by half; for those with a dedicated face, the size is doubled. This is like having battlements original: 堞 die, the notched parapets atop the tower. that face directly outward while the structure itself turns inward.

However, current builders do not project the towers straight out from the wall, nor do they point the battlements directly outward. Instead, they simply pile earth between the two walls, sloping it upward. Because the placement is wrong, the lines of fire original: 矢道 shidao, literally "arrow paths," referring to the clear trajectory required for projectiles. are all oblique. Towers are intended to protect the walls, but if the projectiles original: 矢石 shishi, literally "arrows and stones." cannot reach their targets, how can they be used for defense?

Furthermore, building only one tower per side is insufficient. As for the number of towers, it depends on the fort's...