Book 14 · 备梯 · Chapter 45
禽滑厘子事子墨子三年，手足胼胝，面目黧黑，役身给使，不敢问欲。子墨子其哀之，乃管酒块脯，寄于大山昧葇坐之，以樵禽子。禽子再拜而叹。子墨子曰：“亦何欲乎？”禽子再拜再拜曰：“敢问守道？”
Qin Huali served Master Mozi for three years. His hands and feet grew thick with calluses, his face and eyes turned dark and weathered; he toiled with his body and performed every errand, never daring to voice his own wishes. Master Mozi pitied him, and so he set out a measure of wine and a slab of dried meat, and going to Mount Tai he placed it on the soft grass and sat down, treating Qin to a rustic feast. Qin bowed twice and sighed. Master Mozi said: "Is there something you desire?" Qin bowed twice again and said: "May I venture to ask about the way of defense?"
子墨子曰：“姑亡，姑亡。古有亓术者，内不亲民，外不约治，以少闲众，以弱轻强，身死国亡，为天下笑。子亓慎之，恐为身姜。”
Master Mozi said: "Let it rest for now, let it rest. In antiquity there were those who possessed such arts; but within they did not cherish the people, and without they did not order their governing. With the few they meddled against the many, with the weak they made light of the strong; their persons died and their states perished, and they became the laughingstock of the world. You must be cautious of this, lest it bring ruin upon your own person."
禽子再拜顿首，愿遂问守道。曰：“敢问客众而勇，烟资吾池，军卒并进，云梯既施，攻备已具，武士又多，争上吾城，为之柰何？”
Qin bowed twice and knocked his head to the ground, wishing to press on and ask about the way of defense. He said: "May I venture to ask: when the attacking enemy are numerous and bold, when they fill in our moat, when their soldiers advance together, when the cloud-ladders are already set up, when their siege equipment is fully prepared and their warriors are many, all vying to mount our city wall, what is to be done about it?"
子墨子曰： “问云梯之守邪？云梯者重器也，亓动移甚难。守为行城，杂楼相见，以环亓中。以适广陜为度，环中藉幕，毋广亓处。行城之法，高城二十尺，上加堞，广十尺，左右出巨各二十尺，高、广如行城之法。
Master Mozi said: "You ask about the defense against cloud-ladders? The cloud-ladder is a heavy piece of equipment, and to move and shift it is very difficult. For the defense, build a forward wall (a movable rampart), with watch-towers interspersed so that they overlook one another, encircling its midst. Take the width and narrowness of the terrain as the measure; spread mat-screens within the encircling space, and do not let its area be too broad. The method for the forward wall: where the city wall is high, make it twenty feet, with battlements added on top; ten feet wide; on the left and right project beams (buttresses) each twenty feet out, with height and width following the method of the forward wall.
为爵穴辉鼠，施荅亓外，机、冲、钱、城，广与队等，杂亓闲以镌、剑，持冲十人，执剑五人，皆以有力者。令案目者视适，以鼓发之，夹而射之，重而射之，披机藉之，城上繁下矢、石、沙、炭以雨之，薪火、水汤以济之，审赏行罚，以静为故，从之以急，毋使生虑。若此，则云梯之攻败矣。
Make sparrow-holes and 'shining rat' loopholes, and spread covering-mats (ta screens) over its outer face. The catapult-engines, battering-rams, 'coins' (caltrop-spikes), and ramparts are made as wide as a squad's frontage; intersperse among them men with chisels and swords. Let ten men handle the rams and five men wield the swords, all chosen from the strong. Order keen-eyed men to watch the enemy, and by the drum signal set them loose: shoot the enemy from both flanks and shoot them again in double volleys; throw down the catapult-engines to crush them. From atop the wall pour down arrows, stones, sand, and charcoal upon them like rain, and reinforce this with firewood-flames and boiling water. Carefully apply rewards and carry out punishments; take calm steadiness as your guiding principle; press the pursuit with urgency, and do not let the enemy gather their wits. If you do this, then the attack by cloud-ladders will be defeated.
守为行堞，堞高六尺而一等，施剑亓面，以机发之，冲至则去之，不至则施之。雀穴三尺而一，蒺藜投必遂而立，以车推引之。
For the defense, build movable battlements: the battlements are six feet high, in single tiers; fix swords on their face, and discharge them by a triggered engine. When the battering-ram comes up, withdraw the battlement; when it does not come, set it out. Make sparrow-holes one every three feet. The caltrops, when thrown, must follow up and be set standing, and use carts to push and pull them.
裾城外，去城十尺，裾厚十尺。伐裾，小大尽本断之，以十尺为传，杂而深埋之，坚筑，毋使可拔。二十步一杀，杀有一鬲，鬲厚十尺，杀有两门，门广五尺。裾门一，施浅埋，弗筑，令易拔。城希裾门而直桀。
Build a palisade-wall outside the city, ten feet out from the city wall, the palisade ten feet thick. In felling timber for the palisade, cut every stake off at the very base, large and small alike; take ten-foot lengths as the standard, set them in mixed disorder and bury them deep, ramming them solid so that they cannot be pulled out. Every twenty paces make a 'killing-place'; each killing-place has one cross-wall (partition), the cross-wall ten feet thick; each killing-place has two gates, the gates five feet wide. There is one palisade-gate, set in only shallowly buried and not rammed firm, so as to make it easy to pull out. The city wall, facing the palisade-gate, stands directly aligned with the stake-traps.
县火，四尺一钩樴，五步一灶，灶门有炉炭。令适人尽入，辉火烧门，县火次之。出载而立，亓广终队。两载之闲一火，皆立而待鼓而然火，即具发之。适人除火而复攻，县火复下，适人甚病，故引兵而去。则令我死士左右出穴门击溃师，令贲士、主将皆听城鼓之音而出，又听城鼓之音而入。因素出兵施伏，夜半城上四面鼓噪，适人必或，有此必破军杀将。以白衣为服，以号相得，若此，则云梯之攻败矣。”
Suspend fire-baskets: every four feet one hooked stake (peg); every five paces one stove, and the stove-mouth holds a brazier of charcoal. When the enemy have all entered, light the fires to burn the gates, with the suspended fires following next. Set out the fire-carriers and stand them up, their breadth spanning the full width of the passage. Between every two fire-carriers place one fire; let all stand and wait for the drum, and then kindle the fires, igniting them all at once. When the enemy put out the fires and attack again, let the suspended fires come down once more; the enemy will be sorely afflicted, and so will withdraw their troops and depart. Then order our death-defying warriors to sally out left and right from the tunnel-gates and strike the routed host; let the brave fighters and the chief commander all heed the sound of the city drum and go out, and again heed the sound of the city drum and come back in. Accordingly send out troops beforehand and set ambushes; at midnight, from atop the wall on all four sides, beat the drums and raise an uproar. The enemy are sure to be thrown into confusion, and with this you will surely smash their army and slay their general. Use white garments for your uniform, and recognize one another by passwords. If you do this, then the attack by cloud-ladders will be defeated."