墨子 MOZI

Qin Zi bowed repeatedly and said: 'May I ask about the situation where the enemy shows superior strength, approaches and climbs the wall, with orders for those who lag behind in the scaling to be punished. They chisel into the wall to create steps and excavate the wall to make shelters. Those at the front don't stop climbing while those behind maintain a rapid fire of arrows. What can be done about this?'

Master Mo replied: 'Are you asking about defence against the ant approach? In launching an ant approach, the general is being very aggressive. The defenders should make use of movable approachers to fire on the attackers, using either mechanical firing devices or hand-drawn bows, boiling water to pour down on them, flaming screens to release over them, and sand and stones to rain down on them. In this way, attack by the ant approach can be defeated.'

In preparing for the ant approach, make 'hanging spleens' using wooden planks 2 cun thick. The width at the front and back should be 3 chi and at the sides 5 chi. The height should be 5 chi. To lower them, construct pulleys, the wheels of which should have a diameter of 1 chi 6 cun. Order one man to take hold of a lance 2 zhang 4 chi long and sharp at both ends, and take up position in the hanging spleen. An iron chain is attached to the upper horizontal timber of the hanging spleen and this is suspended from the pulley above. Order four strong men to lower and raise it and not to leave their posts. Set up hanging spleens at intervals of approximately 20 bu, but when the attacking forces are at hand, reduce this to 6 bu.

Make rope-bound screens that are 1 zhang 2 chi in both width and length and have a horizontal timber above. Use thick hempen rope to bind them up and smear them with a covering of mud. Use an iron chain hooked on to both ends to suspend them. When the enemy makes an ant approach to the wall, set fire to the screens and drop them over the enemy. Linked flails, sand and fire all stop them. Take two cart wheels and bind them to a large piece of wood, the distance between the axle-shafts being wide, and oppose them. Both ends of the large piece of wood are sharpened, and both the wood and the wheels are everywhere coated with mud. The space between is filled with twigs of elm or hemp, while at the sides there are brambles. This apparatus is called a 'fire-thrower.' It is also called a 'heat transferrer,' and is placed facing the enemy troops. If the enemy scales the wall, set fire to the heat transferrer, cut its ropes and let it fall. Then give the order for brave warriors to follow it and rout the enemy, taking the heat transferrer as a forerunner to the brave warriors. Those on the wall should immediately repair the damage to the wall.

Below the wall put an adequate number of sharpened wooden stakes, each 5 chi long and greater than half a span in circumference, all sharp at the ends. Make five rows with a distance between the rows of 3 chi and bury them to a depth of 3 chi set upright like dog's teeth. Prepare linked maces 5 chi in length and roughened over 1 cun. Prepare flails 2 chi in length and 6 cun in circumference. The length of the rope should be 2 chi. Prepare hammers with handles 6 chi long and a head that is 1 chi 5 cun long. Prepare axes with handles 6 chi long; the blades must be sharp.

Prepare screens 1 zhang 2 chi wide and 1 zhang 6 chi long and suspend them by an anterior cross-member which projects 4 chi. The place of connection at either end must overhang by 1 chi to the right and left, but don't let it be unequal like fish scales. A large rope 2 zhang 6 chi long is attached to the centre of the posterior cross-member. The screen is exposed in an unconfined place and filled with pieces of wood which are kept dry. The screen should have a framework to allow the air to circulate above and below.

Where the parapet is damaged and thought likely to collapse, first bury pieces of wood, one every 10 chi. If the parapet does collapse, cut pieces of wood and attach cross-pieces on to the well-buried posts. The attached pieces should be 8 chi long, 7 cun wide and have a diameter of 1 chi. They should be securely attached and then lowered. Nail them and cut them.

On the wall, set up wooden towers with piles of stones, and hang screens on the inside of the pillars but not on the outside.

Make an oak palisade buried to a depth of 4 chi and with a height of 10 zhang. In it long and short timbers are mixed together. The upper ends are sharpened and the outer surface thickly covered with mud.

On the wall, have retractable walkways and suspended screens. At the corners, make towers. The towers must be of two storeys. Every 5 bu there should be a pile of earth, not less than twenty baskets. At a distance of 3 chi below the parapets excavate holes at intervals of 10 chi and widest towards the exterior. With respect to changing direction on the wall, quickly prepare the moving towers, pools of water and pitchers of hide. If the enemy scales the wall and those soldiers undertaking the attack are unable to effect a timely retreat and so leave behind military equipment, it should be dealt with according to military conventions. Also there should be use of fire and smoke.

In general, among the methods of repelling an ant approach, there is the setting-up of barriers outside the wall at a distance of 10 chi from it. A barrier should be 10 chi thick. The method for cutting down timber for a barrier is to take everything large or small and cut it at the root, then cut it to 10 chi lengths. The pieces are gathered together and buried deeply in the ground to create a strong construction that cannot be pulled up.

Every 20 bu, there should be one sha with an internal partition 10 chi thick. A sha has two gates, each being 5 chi wide. A small part of the gate timbers is buried but not strongly, allowing them to be easily pulled up. Opposite the gates of the barrier, set up a palisade.

Have hanging fires with a hook every 4 chi. Have one furnace every 5 bu. By the doors of the furnaces have braziers with charcoal. The enemy soldiers are allowed to enter fully, upon which smoke and fire are applied to the gates with hanging fires to follow. Send out carriers and set them up, their width being equivalent to that of the enemy line. Between two carriers, there should be one fire. When everything is set up, the sound of the drum is awaited and upon its occurrence, the fires are lit and thrown down all together. If the enemy should avoid the fire and attack again, the hanging fires are again hurled down, bringing the enemy great distress.

When the enemy army is forced to withdraw, give the order for our crack troops on all sides to go forth from the sally ports and attack the fleeing army. Give the order to these brave men and their general all to go forth when they hear the drum sound on the wall and to return when they hear the drum sound again. As before, when the soldiers and general go forth, set up a diversion. In the middle of the night, make a clamour of drums from all sides on the walls. This must create doubt in the hearts of the enemy, and you will rout their army and kill the general. Put on white garments as clothes and communicate with each other by calls.