Wubei Zhi (Vol. 47)

Treatise on Armament Technology, Volume 23

In defense, regarding walls constructed of brick and stone: when the enemy original: "賊" (zei); literally "thieves" or "bandits," the standard term used for rebels or invading forces in this period. is still far away, it is inconvenient for the residents to be moved; however, once the enemy is close, their houses must be demolished. If hundreds of the enemy hide behind the ridges of rooftops to shoot at the city defenders, or if the enemy masses break through the interior walls of houses to carry ladders to the base of the city wall, they can climb up directly. Alternatively, they might take soil from within civilian houses to build ramps against the wall, widening the approach to ascend. In such cases, one is helpless to stop them. If there are buildings within ten feet original: "一丈" (yi zhang); approximately 3.2 meters or 10.5 feet during the Ming dynasty. of the city, and the wall itself is lower than the interior of those houses, that city is indefensible.

Merchandise such as bamboo and timber is often stored near the outer city walls original: "附郭" (fu guo); the suburban areas immediately adjacent to the main city fortifications.. If these are not moved, they will all serve as tools for the enemy's siege. One must require all merchants to take goods already brought ashore and, according to the deadline, quickly transport them into the city to be offered for sale.

As for those rafts still on the water, they should be moved fifty or sixty li A li is roughly 500 meters; this distance is about 25–30 kilometers. away to hidden and secluded small harbors for temporary storage, waiting for the enemy to pass before resuming business. If these orders are violated, all such goods shall be confiscated for official public use.

In the various villages and towns outside the city, wealthy households store rice in their homes; this, along with—