Book 14 · 备城门 · Chapter 43
禽滑厘问于子墨子曰：“由圣人之言，凤鸟之不出，诸侯畔殷周之国，甲兵方起于天下，大攻小，强执弱，吾欲守小国，为之柰何？”子墨子曰：“何攻之守？”禽滑厘对曰：“今之世常所以攻者：临、钩、冲、梯、堙、水、穴、突、空洞、蚁傅、轒轀轩车，敢问守此十二者柰何？”子墨子曰：“我城池修，守器具，樵粟足，上下相亲，又得四邻诸侯之救，此所以持也。且守者虽善，而君不用之，则犹若不可以守也。若君用之守者，又必能乎守者，不能而君用之，则犹若不可以守也。然则守者必善而君尊用之，然后可以守也。
Qin Guli asked Master Mozi: "According to the words of the sages, the phoenix bird does not appear, the feudal lords rebel against the states of Yin and Zhou, and armored troops are arising everywhere under Heaven, the great attacking the small and the strong subjugating the weak. I wish to defend a small state—how should it be done?" Master Mozi said: "Defend against what kind of attack?" Qin Guli replied: "In the present age the usual means of attack are: the lin (the approaching siege-tower), the gou (grappling-hook engine), the chong (battering-ram), the ti (scaling-ladder), the yin (earthen ramp), water (flooding), the xue (mining tunnel), the tu (sudden sortie tunnel), the kongdong (hollow-out sapping), the yifu (ant-swarm assault, climbing the walls like ants), and the fenwen and xuanche (the covered ramming-cart and the screened wagon). I venture to ask: how does one defend against these twelve?" Master Mozi said: "If our city walls and moats are well-maintained, our defensive implements are complete, firewood and grain are sufficient, superiors and inferiors are mutually attached, and we also obtain the rescue of the feudal lords on our four borders—these are what enable us to hold out. Yet even if the defender is capable, if the ruler does not employ him, it is still as though the city cannot be defended. And if the ruler does employ him for the defense, the defender must also be competent at defending; if he is incompetent and the ruler employs him, it is still as though the city cannot be defended. Therefore the defender must be capable and the ruler must honor and employ him—only then can the city be defended.
凡守圉城之法，厚以高，壕池深以广，楼撕修，守备缮利，薪食足以支三月以上，人众以选，吏民和，大臣有功劳于上者多，主信以义，万民乐之无穷。不然，父母坟墓在焉；不然，山林草泽之饶足利；不然，地形之难攻而易守也；不然，则有深怨于适而有大功于上；不然则赏明可信而罚严足畏也。此十四者具，则民亦不宜上矣。然后城可守。十四者无一，则虽善者不能守矣。
In general, the method of defending a beleaguered city: the walls should be thick and high, the moats deep and broad, the watchtowers well-built, the defensive provisions repaired and made effective, the firewood and food sufficient to last three months or more, the men numerous and selected, the officials and people in harmony, the great ministers many in their meritorious service to the ruler, the lord trustworthy and just, and the myriad people delighting in him without end. If not this, then there are the tombs of fathers and mothers within the city; if not this, then the abundance of mountains, forests, grasslands, and marshes is ample and profitable; if not this, then the terrain is difficult to attack and easy to defend; if not this, then there is deep hatred toward the enemy and great merit toward the ruler; if not this, then rewards are clear and trustworthy and punishments severe enough to be feared. When these fourteen things are present, then the people too will not turn against their superiors. Only then can the city be defended. If even one of the fourteen is lacking, then even a capable man cannot defend it.
故凡守城之法，备城门为县门沈机，长二丈，广八尺，为之两相如；门扇数令相接三寸，施土扇上，无过二寸。堑中深丈五，广比扇，堑长以力为度，堑之末为之县，可容一人所。客至，诸门户皆令凿而慕孔。孔之。各为二幕二，一凿而系绳，长四尺。城四面四隅皆为高楼磿撕，使重室子居亓上，磿适，视亓态状，与亓进左右所移处，失磿斩。
Therefore, in general, the method of defending a city: in fortifying the city gate make a portcullis (xuanmen, suspended gate) with a sinking mechanism, two zhang long (a zhang is ten chi, roughly 2.3 m) and eight chi wide (a chi being roughly 23 cm), the two leaves made to match each other; the gate leaves let several of them join together to within three cun (a cun being roughly 2.3 cm), and apply earth onto the leaves no more than two cun thick. In the trench have a depth of one zhang five chi, the width equal to the leaves; the length of the trench is measured according to the available strength, and at the end of the trench make the suspended part, able to hold one man. When the enemy arrives, let all the gate-houses be bored through and have screen-holes made. Bore them, and for each make two screens, one a bored hole with a rope tied to it, four chi long. On the four faces and four corners of the city all make high watchtowers and lookout-posts, and have sons of substantial households dwell upon them to scout the enemy, observing the enemy's appearance and condition and the places to which they advance and shift left and right; one who fails in the scouting is to be beheaded.
适人为穴而来，我亟使穴师选士，迎而穴之，为之且内弩以应之。
When the enemy makes a mine-tunnel and comes, we must quickly send mining-masters and selected men to meet and counter-mine them, and prepare crossbows positioned within to respond to them.
民室材木瓦石，可以益城之备者，尽上之。不从令者斩。
Of the people's houses—timber, tiles, and stone that can add to the city's defensive provisions—let all of it be brought up. Those who do not obey the order are to be beheaded.
皆筑，七尺一居属，五步一垒。五筑有铁。长斧，柄长八尺。十步一长镰，柄长八尺。十步一斫，长椎，柄长六尺，头长尺，兑亓两端。三步一大铤，前长尺，蚤长五寸。两铤交之置如平，不如平不利，兑亓两末。穴队若冲队，必审如攻队之广狭，而令邪穿亓穴，令亓广必夷客队。
Build all of it up: every seven chi place a support post, every five bu (a bu, pace, being about six chi) set a rampart-pile. For every five builders have iron tools. The long axe has a haft eight chi long. Every ten bu have one long sickle with a haft eight chi long. Every ten bu have one chopping-tool, and a long mallet with a haft six chi long, its head one chi long, sharpened at both ends. Every three bu have one large pike, the fore-part one chi long, the barb five cun long. Two pikes crossed are set so they lie level; if not level they are not effective; sharpen their two tips. For mine-shafts and ram-passages, one must carefully gauge the breadth and narrowness of the attacker's passage, and have one's own mine bored obliquely through, making one's own width necessarily equal to the attacker's passage.
疏束树木，令足以为柴抟，贯前面树，长丈七尺一以为外面，以柴抟从横施之，外面以强涂，毋令土漏。令亓广厚，能任三丈五尺之城以上。以柴木土稍杜之，以急为故。前面之长短，豫蚤接之，令能任涂，足以为堞，善涂亓外，令毋可烧拔也。
Bundle and bind trees loosely so that they suffice to make faggot-bundles, threading them through the front-facing trees, one zhang seven chi long, to make the outer face; lay the faggot-bundles crosswise and lengthwise, plaster the outer face thickly so that no earth leaks through. Make it broad and thick enough to bear a wall of three zhang five chi or more. Block it up gradually with firewood, timber, and earth, taking urgency as the rule. The length of the front face—prepare and join it in advance, so that it can bear the plaster and suffice to serve as battlements; plaster its exterior well, so that it cannot be burned or pulled out.
大城丈五为闺门，广四尺。
A great city makes a small postern gate (gui-men) one zhang five chi high and four chi wide.
为郭门，郭门在外，为衡，以两木当门，凿亓木维敷上堞。
Make the outer-wall gate (guo-men), the outer-wall gate being on the outside; make a cross-bar, with two timbers set against the gate, boring the timbers and fastening cords over the battlements.
为斩县梁，令穿，断城以板桥，邪穿外，以板次之，倚杀如城报。城内有傅堞，因以内堞为外。凿亓闲，深丈五尺，室以樵，可烧之以待适。
Make a cut-suspended beam, having it bored through, cutting the wall with a plank bridge, bored obliquely on the outside, with planks set in succession, sloping down and tapering like the wall's return. Within the city there are attached battlements; accordingly use the inner battlements as the outer. Bore the gap between them, fifteen chi deep, and store firewood in it, so it can be burned to await the enemy.
令耳属城，为再重楼。下凿城外堞内深丈五，广丈二。楼若令耳，皆令有力者主敌，善射者主发，佐以厉矢。
Have ear-towers (er, projecting platforms) attached to the wall, making double-tiered towers. Below, bore from the outer battlement inward, fifteen chi deep and twelve chi wide. The towers and ear-towers: in all of them have strong men take charge of facing the enemy, good archers take charge of shooting, assisted with whetted arrows.
治裾诸，延堞，高六尺，部广四尺，皆为兵弩简格。
Construct ju-screens and extend the battlements, six chi high, each section four chi wide, all made with racks for arms and crossbows.
转射机，机长六尺，狸一尺。两材合而为之轀，轀长二尺，中凿夫之为通臂，臂长至垣。二十步一，令善射者佐之，令一人下上之勿离。
The swivel shooting-engine (zhuanshe-ji): the engine is six chi long, with one chi buried. Two timbers joined make the wen (the cradle); the wen is two chi long, and through its middle is bored a socket making a connecting arm, the arm long enough to reach the parapet. One every twenty bu, with a good archer to assist it, and have one man raise and lower it without leaving it.
城上百步一楼，楼四植，植皆为通舄，下高丈，上九尺，广、袤各丈六尺，皆为文。三十步一突，九尺，广十尺，高八尺，凿广三尺，袤二尺，为文。
On the wall every hundred bu one tower, the tower with four uprights, the uprights all made with through-sockets, below ten chi high, above nine chi, each one zhang six chi in width and length, all made interlaced. Every thirty bu one sortie-outlet (tu), nine chi, ten chi wide and eight chi high, the bore three chi wide and two chi long, made interlaced.
城上为攒火，矢长以城高下为度，置火亓末。
On the wall make fire-arrows in clusters (cuanhuo); the arrows are measured according to the height of the wall, with fire placed at their tips.
城上九尺一弩、一戟、一椎、一斧、一艾，皆积絫石、蒺藜。
On the wall every nine chi one crossbow, one halberd, one mallet, one axe, one reaping-blade, all with stacked stones and caltrops piled up.
渠长丈六尺，夫长丈二尺，臂长六尺，亓狸者三尺，树渠毋傅堞五寸。
The qu (mantlet-engine) is one zhang six chi long, the prop one zhang two chi long, the arm six chi long, with three chi buried; plant the qu no closer than five cun from the battlements.
藉莫长八尺，广七尺，亓木也广五尺，中藉苴为之桥，索亓端；适攻，令一人下上之，勿离。
The screen-mat (jiemo) is eight chi long and seven chi wide, its wood being five chi wide, with mat-padding in the middle made into a screen, with cords at its ends; when the enemy attacks, have one man raise and lower it without leaving it.
城上二十步一藉车，当队者不用此数。
On the wall every twenty bu one catapult-cart (jieche); where the enemy's main column attacks, this count does not apply.
城上三十步一砻灶。
On the wall every thirty bu one grinding-stove.
持水者必以布麻斗、革盆，十步一。柄长八尺，斗大容二斗以上到三斗。敝綌、新布长六尺，中拙柄，长丈，十步一，必以大绳为箭。
Those who carry water must use hemp-cloth dippers and leather basins, one every ten bu. The handle is eight chi long, the dipper's capacity from two dou upward to three dou (a dou being roughly two liters). Worn coarse-cloth and new cloth six chi long, with a handle fixed in the middle one zhang long, one every ten bu; one must use thick rope as the binding.
城上十步一鈂。
On the wall every ten bu one iron digging-tool (chen).
水缶，容三石以上，小大相杂。盆、蠡各二财。
Water jars, holding three shi or more (a shi being a stone-weight/measure, here a large jar), large and small intermixed. Basins and ladles, two of each set aside.
为卒乾饭，人二斗，以备阴雨，面使积燥处。令使守为城内堞外行餐。
Make dried cooked rice for the soldiers, two dou per man, to provide against overcast and rainy weather, but have it stockpiled in a dry place. Have the defenders set up a meal-line within the city's battlements and outside them.
置器备，杀沙砾铁，皆为坏斗。令陶者为薄缶，大容一斗以上至二斗，即用取，三秘合束。
Set out the equipment and provisions: pulverize sand, gravel, and iron, all made into smashing-pellets. Have the potters make thin pots, large enough to hold one dou up to two dou; when needed take them up—three are bound together as a bundle.
坚为斗城上隔。栈高丈二，剡亓一末。
Firmly make smashing-pellets, and partition-screens on the wall. The plank-fence is one zhang two chi high, sharpened at one end.
为闺门，闺门两扇，令可以各自闭也。
Make a small postern gate (gui-men); the postern gate has two leaves, made so that each can be closed by itself.
救闉池者，以火与争，鼓橐，冯埴外内，以柴为燔。
To rescue against the flooded moat, fight it with fire, working bellows-bags, pressing earth inside and out, using firewood to make the blaze.
灵丁，三丈一，犬牙施之。十步一人，居柴内帑，柴半，为狗犀者环之。墙七步而一。
The ling-ding (warding-stakes), one every three zhang, set in dog-tooth (zigzag) array. One man every ten bu dwells within the firewood store; with the firewood half-used, ring it about with dog-fang spikes. A wall has one every seven bu.
救车火，为熛矢射火城门上，凿扇上为栈，涂之，持水麻斗、革盆救之。门扇薄植，皆凿半尺，一寸一涿弋，弋长二寸，见一寸，相去七寸，厚涂之以备火。城门上所凿以救门火者，各一垂水，容三石以上，小大相杂。门植关必环锢，以锢金若铁鍱之。门关再重，鍱之以铁，必坚。梳关，关二尺，梳关一苋，封以守印，时令人行貌封，及视关入桓浅深。门者皆无得挟斧、斤、凿、锯、椎。
To rescue against fire on the carts: when blazing arrows shoot fire onto the top of the city gate, bore the upper part of the gate-leaves to make a plank-frame, plaster it, and rescue it with hemp water-dippers and leather basins. The gate-leaves' thin uprights—bore them all half a chi, with a peg-nail every cun, the pegs two cun long with one cun showing, seven cun apart from each other, and plaster thickly over them to provide against fire. The places bored above the city gate to rescue the gate from fire—each has one hanging water-vessel holding three shi or more, large and small intermixed. The gate's upright bar-bolt must be encircled and fastened, fastened with bronze or sheathed with iron. The gate-bar is doubled, sheathed with iron, and must be firm. The comb-bolt: the bar is two chi, the comb-bolt has a single device, sealed with the defender's seal; from time to time have men go round to inspect the seal and to check how deep the bolt enters the post. The gate-keepers must none of them carry axes, hatchets, chisels, saws, or mallets.
城上二步一渠，渠立程，丈三尺，冠长十丈，辟长六尺。二步一荅，广九尺，袤十二尺。
On the wall every two bu one qu (mantlet); the qu stands on a stand, one zhang three chi, its cap ten zhang long, the side-piece six chi long. Every two bu one da (a shield-screen of woven matting), nine chi wide and twelve chi long.
二步置连梃、长斧、长椎各一物；枪二十枚，周置二步中。
Every two bu place a linked flail, a long axe, and a long mallet, one of each item; twenty spears, set all around within the two-bu span.
二步一木弩，必射五十步以上。及多为矢，即毋竹箭，以楛、桃、柘、榆，可。盖求齐铁夫，播以射冲及栊枞。
Every two bu one wooden crossbow, which must shoot fifty bu or more. And make many arrows; if there are no bamboo arrows, then ku-wood, peach, zhe-wood, or elm will do. Generally seek to fit them with iron arrowheads, and loose them to shoot the ram-engine (chong) and the long-tower-engine (longcong).
二步积石，石重千钧以上者，五百枚。毋百，以亢疾犁、壁，皆可善方。
Every two bu stockpile stones; of stones weighing a thousand jun or more (a jun being thirty jin), five hundred pieces. Even short of a hundred, use them to ward off the sharp-plow engine and the wall-engine—all these may be well dealt with.
二步积苙，大一围，长丈，二十枚。
Every two bu stockpile straw-bundles, one arm-span around and one zhang long, twenty pieces.
五步一罂，盛水有奚，奚蠡大容一斗。
Every five bu one earthen jar (ying) holding water, with a ladle, the ladle holding one dou.
五步积狗尸五百枚，狗尸长三尺，丧以弟，瓮亓端，坚约弋。
Every five bu stockpile five hundred dog-corpse stakes (gou-shi); the gou-shi is three chi long, bound with bamboo, capped at the end, firmly fastened with a peg.
十步积抟，大二围以上，长八尺者二十枚。
Every ten bu stockpile faggot-bundles, two arm-spans around or more, eight chi long, twenty pieces.
二十五步一灶，灶有铁鐕容石以上者一，戒以为汤。及持沙，毋下千石。
Every twenty-five bu one stove, the stove having one iron cauldron holding a shi or more, kept ready to make boiling water. And keep on hand sand, no less than a thousand shi.
三十步置坐侯楼，楼出于堞四尺，广三尺，广四尺，板周三面，密傅之，夏盖亓上。
Every thirty bu place a seated lookout-tower, the tower projecting four chi beyond the battlements, three chi wide [front] and four chi wide, with planks all around three faces, closely fitted, and in summer a covering over the top.
五十步一藉车，藉车必为铁纂。
Every fifty bu one catapult-cart (jieche); the catapult-cart must be fitted with iron bindings.
五十步一井屏，周垣之，高八尺。
Every fifty bu one well-shelter, walled all around, eight chi high.
五十步一方，方尚必为关龠守之。
Every fifty bu one cabinet (fang); the cabinet's top must have a bolt-and-lock to guard it.
五十步积薪，毋下三百石，善蒙涂，毋令外火能伤也。
Every fifty bu stockpile firewood, no less than three hundred shi, well covered with plaster, so that no fire from outside can harm it.
百步一栊枞，起地高五丈，三层，下广前面八尺，后十三尺，亓上称议衰杀之。
Every hundred bu one long-tower-engine (longcong), rising five zhang high from the ground, in three tiers, the lower part eight chi wide at the front face and thirteen chi at the rear, its upper part tapered in proportion as deemed fit.
百步一木楼，楼广前面九尺，高七尺，楼囱居坫，出城十二尺。
Every hundred bu one wooden tower, the tower nine chi wide at the front face, seven chi high, with the tower's window placed at the platform, projecting twelve chi beyond the wall.
百步一井，井十瓮，以木为系连。水器容四斗到六斗者百。
Every hundred bu one well, the well with ten jars, joined together by wooden links. Water-vessels holding four dou to six dou, a hundred of them.
百步一积杂秆，大二围以上者五十枚。
Every hundred bu stockpile mixed stalks, of those two arm-spans around or more, fifty pieces.
百步为橹，橹广四尺，高八尺。为冲术，
Every hundred bu make a wooden screen-shield (lu); the lu is four chi wide and eight chi high. Make ram-roads (passages for engines).
百步为幽窦，广三尺高四尺者千。
Every hundred bu make a hidden sap-hole (youdou), three chi wide and four chi high, a thousand of them.
二百步一立楼，城中广二丈五尺二，长二丈，出枢五尺。
Every two hundred bu one standing tower, within the city two zhang five chi two [in width] and two zhang long, the pivot projecting five chi.
城上广三步到四步，乃可以为使斗。俾倪广三尺，高二尺五寸。陛高二尺五，广长各三尺，远广各六尺。城上四隅童异高五尺四尉舍焉。
On the wall, three to four bu in width is then enough to fight upon. The crenel-screens (bini) are three chi wide and two chi five cun high. The steps are two chi five cun high, three chi each in length and breadth, with the rise and tread each six chi. At the four corners of the wall the children's [lookout] platforms rise five chi, where the four wei-officers are quartered.
城上七尺一渠，长丈五尺，狸三尺，去堞五寸，夫长丈二尺，臂长六尺。半植一凿，内后长五寸。夫两凿，渠夫前端下堞四寸而适。凿渠、凿坎，覆以瓦，冬日以马夫寒，皆待命，若以瓦为坎。
On the wall every seven chi one qu (mantlet), one zhang five chi long, with three chi buried, five cun from the battlements; the prop one zhang two chi long, the arm six chi long. Half the upright has one socket, recessed five chi to the rear. The prop has two sockets; the prop's front end below the battlement is four chi, and that is right. Bore the qu-sockets and bore pits, cover them with tiles, and in winter use horse-droppings to ward off cold, all awaiting orders; or use tiles to make the pits.
城上千步一表，长丈，弃水者操表摇之。五十步一厕，与下同圂。之厕者，不得操。
On the wall every thousand bu one signal-pole, one zhang long; one who discards water grasps the pole and shakes it. Every fifty bu one latrine, sharing a privy-pit with those below. Those going to the latrine are not permitted to carry [arms].
城上三十步一藉车，当队者不用。
On the wall every thirty bu one catapult-cart (jieche); where the enemy's main column attacks, it is not used [by this count].
城上五十步一道陛，高二尺五寸，长十步。城上五十步一楼，楼撕必再重。
On the wall every fifty bu one ramp-stairway, two chi five cun high and ten bu long. On the wall every fifty bu one tower, the tower-lookout must be double-tiered.
土楼百步一，外门发楼，左右渠之。为楼加藉幕，栈上出之以救外。
Earthen towers, one every hundred bu; an outer-gate sortie-tower, with mantlets to its left and right. For the tower add a screen-mat, projecting from the plank-frame to rescue the outside.
城上皆毋得有室，若也可依匿者，尽除去之。
On the wall there must be no chambers; if there is anything one could rely on for concealment, remove all of it.
城下州道内百步一积薪，毋下三千石以上，善涂之。
On the road-circuit below the wall, every hundred bu one stockpile of firewood, no less than three thousand shi, well plastered.
城上十人一什长，属一吏士、一帛尉。
On the wall every ten men one squad-leader, attached to one officer-soldier and one silk-banner officer (boshu, a tally-officer).
百步一亭，高垣丈四尺，厚四尺，为闺门两扇，令各可以自闭。亭一尉，尉必取有重厚忠信可任事者。
Every hundred bu one watch-post, with a high wall one zhang four chi [high] and four chi thick, with a small postern gate of two leaves, made so each can close by itself. Each post has one wei-officer; the wei-officer must be one chosen as grave, substantial, loyal, and trustworthy, capable of being entrusted with affairs.
二舍共一井爨，灰、康、秕、秠马矢，皆谨收藏之。
Every two quarters share one well and cooking-fire. Ash, chaff, blighted grain, husks, and horse-droppings—all are to be carefully collected and stored.
城上之备：渠谵、藉车、行栈、行楼、到，颉皋、连梃、长斧、长椎、长兹、距、飞冲、县口、批屈。楼五十步一，堞下为爵穴，三尺而一为薪皋，二围长四尺半必有洁。
The equipment for the wall: the qu-mantlet, the catapult-cart, the movable plank-fence, the movable tower, the daoward, the lifting-lever (jiegao), the linked flail, the long axe, the long mallet, the long pike, the warding-pole (ju), the flying-ram, the suspended-mouth device, and the bending-hook. Towers one every fifty bu, below the battlements make sparrow-holes (jue-xue), one every three chi, made as firewood-levers, two arm-spans around and four chi and a half long, each necessarily clean.
瓦石：重二升以上，上。城上沙，五十步一积。灶置铁鐕焉，与沙同处。
Tiles and stones: those weighing two sheng or more (a sheng being a measure of volume; here by weight) go up onto the wall. Sand on the wall, one stockpile every fifty bu. Set an iron cauldron at the stove, placed together with the sand.
木大二围，长丈二尺以上，善耿亓本，名曰长从，五十步三十。木桥长三丈，毋下五十。复使卒急为垒壁，以盖瓦复之。
Timber two arm-spans around and one zhang two chi long or more, with its base well charred, called the chang-cong (long-follower), thirty for every fifty bu. Wooden bridges three zhang long, no fewer than fifty. Again have the soldiers urgently make rampart-walls, covered over with tiles.
用瓦木罂，容十升以上者，五十步而十，盛水，且用之。五十二者十步而二。
Use tile-and-wood jars holding ten sheng or more, ten for every fifty bu, filled with water and ready for use. The fifty-two [vessels?]—two every ten bu.
城下里中家人，各葆亓左右前后，如城上。城小人众，葆离乡老弱国中及也大城。
The households of the wards below the wall each guard their own left, right, front, and rear, as on the wall. If the city is small and the people many, move the old and weak of the outlying villages into the state center and into the great city.
寇至，度必攻，主人先削城编，唯勿烧寇在城下，时换吏卒署，而毋换亓养，养毋得上城。寇在城下，收诸盆瓮，耕积之城下，百步一积，积五百。
When the enemy arrives and it is reckoned they will surely attack, the host first pares away the city's records/markings; only do not burn them while the enemy is below the wall. From time to time rotate the officers' and soldiers' assignments, but do not rotate their cooks, and the cooks must not be allowed up onto the wall. While the enemy is below the wall, collect all the basins and jars, and till and pile them up below the wall, one stockpile every hundred bu, five hundred per stockpile.
城门内不得有室，为周官桓吏，四尺为倪。行栈内閈，二关一堞。
Inside the city gate there must be no chambers; make the round patrol-posts and post-guards, four chi to make the small wall (ni). The movable plank-fence is enclosed inside; two bars and one battlement.
除城场外，去池百步，墙垣树木小大俱坏伐，除去之。寇所从来若昵道、傒近，若城场，皆为扈楼。立竹箭天中。
Clear the field outside the city; for a hundred bu from the moat, walls, fences, and trees large and small are all to be torn down, felled, and removed. Wherever the enemy may come from—whether a near road, a short cut, or close approach, or the city's field—all are to have hu-towers (covered lookout-towers) made. Plant bamboo arrows up in the midst of the sky [i.e., set them high].
守堂下为大楼，高临城，堂下周散，道中应客，客待见，时召三老在葆宫中者，与计事得先。行德计谋合，乃入葆。葆入守，无行城，无离舍。诸守者，审知卑城浅池，而错守焉。晨暮卒歌以为度，用人少易守。
Below the defense-hall make a great tower, high and overlooking the wall; below the hall is an open circuit, and in the roadway respond to visitors. When a guest waits to be received, at that time summon the Three Elders (san-lao) who are in the citadel-palace, and let them be foremost in deliberating affairs. If their conduct and virtue and their plans accord, then admit them into the citadel. Once admitted to the defense, they do not patrol the wall and do not leave their quarters. All the defenders should carefully know the low parts of the wall and the shallow parts of the moat, and station the defense accordingly. Use the soldiers' singing at dawn and dusk as a measure of time; using few men makes it easy to defend.
守法：五十步丈夫十人、丁女二十人、老小十人，计之五十步四十人。城下楼卒，率一步一人，二十步二十人。城小大以此率之，乃足以守圉。
The rule of defense: per fifty bu, ten grown men, twenty able-bodied women, ten old and young—reckoning it, fifty bu to forty persons. The tower-soldiers below the wall, at a rate of one man per bu, twenty men per twenty bu. The size of the city is reckoned by this rate, and is then sufficient to defend the besieged.
客冯面而蛾傅之，主人则先之知，主人利，客适。客攻以遂，十万物之众，攻无过四队者，上术广五百步，中术三百步，下术五十步。诸不尽百五步者，主人利而客病。广五百步之队，丈夫千人，丁女子二千人，老小千人，凡四千人，而足以应之，此守术之数也。使老小不事者，守于城上不当术者。
When the enemy presses upon a face and swarms it ant-like, if the host knows of it beforehand, the host has the advantage and the enemy is in trouble. The enemy attacks by storming columns; out of a host of a hundred thousand, the attack does not exceed four columns: the broad approach is five hundred bu wide, the medium approach three hundred bu, the narrow approach fifty bu. For all approaches not fully a hundred and five bu, the host has the advantage and the enemy suffers. For a column on a five-hundred-bu-wide approach, a thousand grown men, two thousand able-bodied women, a thousand old and young—four thousand persons in all—suffice to respond to it; this is the calculation of the defensive approaches. Have the old and young who are unfit for service guard the parts of the wall not facing an approach.
城持出必为明填，令吏民皆智知之。从一人百人以上，持出不操填章，从人非亓故人，乃亓稹章也，千人之将以上止之，勿令得行。行及吏卒从之，皆斩，具以闻于上。此守城之重禁之，夫奸之所生也，不可不审也。
When the city sends anyone out, there must be a clear pass-tally, and let officials and people all know it. When one man or a hundred men or more go out, if they go out without holding the pass-token, or the accompanying persons are not their proper men, or their tally is [false], then the commander of a thousand men or above stops them and does not let them pass. If they proceed, the officers and soldiers who let them through are all beheaded, and the whole matter reported to the superior. This is the grave prohibition of city defense, for it is the source from which treachery arises, and it cannot but be carefully watched.
城上为爵穴，下堞三尺，广亓外，五步一。爵穴大容苴，高者六尺，下者三尺，疏数自适为之。塞外堑，去格七尺，为县梁。城笮陜不可堑者，勿堑。城上三十步一聋灶，人擅苣长五节。寇在城下，闻鼓音，燔苣，复鼓，内苣爵穴中，照外。
On the wall make sparrow-holes (jue-xue), three chi below the battlements, widened on the outside, one every five bu. The sparrow-hole is large enough to hold a torch, the high ones six chi, the low ones three chi, spaced sparse or dense as suits. Block the outer trench, and seven chi from the rack make a suspended beam. Where the wall is narrow and cannot be trenched, do not trench it. On the wall every thirty bu one deaf-stove (long-zao, a sunken stove). Each man holds a torch five joints long. While the enemy is below the wall, on hearing the drum-sound, light the torch, and at the second drum, put the torch into the sparrow-hole to illuminate the outside.
诸藉车皆铁什，藉车之柱长丈七尺，亓狸者四尺；夫长三丈以上，至三丈五尺，马颊长二尺八寸，试藉车之力而为之困，失四分之三在上。藉车，夫长三尺，四二三在上，马颊在三分中。马颊长二尺八寸，夫长二十四尺，以下不用。治困以大车轮。藉车桓长丈二尺半，诸藉车皆铁什，复车者在之。
All the catapult-carts are fitted with iron gear: the catapult-cart's post is one zhang seven chi long, with four chi buried; the prop is three zhang or more, up to three zhang five chi; the horse-cheek (pivot-piece) is two chi eight cun long. Test the force of the catapult-cart and make the frame for it, with three quarters above. For the catapult-cart, the prop being three chi, four [parts], two-thirds above, the horse-cheek in the middle third. The horse-cheek two chi eight cun long, the prop twenty-four chi; below this, do not use. Make the frame from a great cart-wheel. The catapult-cart's post is one zhang two chi and a half long; all the catapult-carts are fitted with iron gear, and the reserve carts are kept on hand.
寇闉池来，为作水甬，深四尺，坚慕狸之。十尺一，覆以瓦而待令。以木大围长二尺四分而早凿之，置炭火亓中而合慕之，而以藉车投之。为疾犁投，长二尺五寸，大二围以上。涿弋，弋长七寸，弋闲六寸，剡亓末。狗走，广七寸，长尺八寸，蚤长四寸，犬耳施之。”
When the enemy comes flooding the moat, make a water-conduit (shuiyong) four chi deep, firmly screened and buried; one every ten chi, covered with tiles and awaiting orders. Take timber a large span around and two chi four [cun] long, and quickly bore it, place charcoal-fire within it and seal it shut, and hurl it with the catapult-cart. As sharp-plow projectiles, make them two chi five cun long, two arm-spans around or more. Peg-spikes, the pegs seven cun long, six cun between pegs, sharpened at the tips. Dog-runners (gou-zou), seven cun wide and one chi eight cun long, the barb four cun long, set with dog-ears."
子墨子曰：“守城之法，必数城中之木，十人之所举为十挈，五人之所举为五挈，凡轻重以挈为人数。为薪樵挈，壮者有挈，弱者有挈，皆称亓任。凡挈轻重所为，吏人各得亓任。城中无食则为大杀。去城门五步大堑之，高地三丈下地至，施贼亓中，上为发梁，而机巧之，比传薪土，使可道行，旁有沟垒，毋可逾越，而出佻且比，适人遂入，引机发梁，适人可禽。适人恐惧而有疑心，因而离。”
Master Mozi said: "The method of defending a city: one must count up the timber in the city. What ten men can lift is reckoned ten loads, what five men can lift is five loads; in general, weight is reckoned in loads to determine the number of men. For making firewood and faggot loads, the strong have their loads and the weak have their loads, each matched to his capacity. In all that the loads' weights are arranged for, each official and man gets his fitting task. If there is no food in the city, then resort to great slaughter [of livestock]. Five bu from the city gate dig a great pit—three zhang on high ground, down to [water] on low ground—and plant spikes within it, above making a movable beam, contriving it with a mechanism, layering firewood and earth over it so that one can pass along it; on the sides have ditches and ramparts that cannot be crossed over, and going out it is light and close-set. When the enemy thereupon enters, pull the mechanism and release the beam, and the enemy can be captured. The enemy, terrified and grown suspicious, will thereupon disperse."