Wujing Zongyao

The book was compiled during the Northern Song dynasty by Zeng Gongliang (曾公亮), Ding Du (丁度) and Yang Weide (楊惟德), whose writing influenced many later Chinese military writers.

It contains the earliest known written chemical formulas for gunpowder, made from saltpeter, sulphur and charcoal along with many added ingredients.

It also describes an early form of the compass (using thermoremanence), and has the oldest illustration of a Chinese flamethrower with a double-action dual-piston cylinder-pump capable of shooting a continuous blast of flame.

[7] A team of scholars worked from 1040 to 1044 to compile the Wujing Zongyao with the intent to collect all known military knowledge[8] and to disseminate it to a wider government audience.

[7] Parts of the Wujing Zongyao were copied from older sources; historian Ralph D. Sawyer calls it "essentially a cut-and-paste job", containing many passages from earlier classical military writings whose original authors are left unidentified, a common practice at the time.

[9] During the Song dynasty, the Wujing Zongyao was appended to two other books: the Xingjun xuzhi and the Baizhan qifa, both written by anonymous authors.

[5] Of these 347 different military treatises from the Song period, only the Wujing Zongyao, the Huqianjing (Tiger Seal Manual) of Xu Dong in 1004 AD, and fragments of similar works found in the later Yongle Dadian, have survived.

[10] The original copy of the Wujing Zongyao was lost during the Jin–Song wars when the invading Jurchens sacked the Northern Song capital of Kaifeng in 1126 AD.

[11] A remaining copy of the Wujing Zongyao was remade into a newly published edition in 1231 AD in the Southern Song dynasty.

Fan wrote the book because he felt that reprints of the Wujing Zongyao circulating at that time were out of date and did not take into account the technological and strategic changes that had occurred since the Song dynasty.

This was a wheeled vehicle that employed differential gearing in order to lock a figurine of an immortal in place on the end of a long wooden staff, the figure having its arm stretched out and always pointing to the southern cardinal direction.

Although the authors of the Wujing Zongyao were mistaken in believing that the design of the south-pointing chariot was not handed down (as it was reinvented during the Song period and combined with an odometer), they described a new device which allowed one to navigate.

To use it, a small bowl filled with water is set up in a windless place, and the fish is laid as flat as possible upon the water-surface so that it floats, whereupon its head will point south.

[17] The later maritime author Zhu Yu wrote of the magnetic needle compass as a means to navigate at sea in his Pingzhou Table Talks of 1119 AD.

[18] The Wujing Zongyao divides Chinese warships into six categories: Tower ships (lou chuan), combat or war junks (dou xian or zhan xian), covered swoopers (meng chong), flying barques (zou ge), patrol boats (you ting), and sea hawk ships (hai hu).

[22] The Wujing Zongyao records detailed descriptions of gunpowder weapons such as incendiary projectiles, smoke bombs, fire arrows, and grenades.

It documents incendiary projectiles containing low-nitrate gunpowder,[23] which were launched from catapults or lowered down from city walls onto besiegers.

Chinese soldiers defending a city under siege would light the incendiary and lower it onto any wooden structure of the invading army to engulf it in fire.

Melt yellow wax and let it stand until clear, then add powdered charcoal and make it into a paste permeating the ball; bind it up with hempen string.

The gunpowder mixture for a bomb was placed within a rigid container that held in the expanding gas, allowing for more powerful explosions.

[36] If the outer coating and inner ball are both included with the second black-powder formula, that would yield a nitrate level of 34.7% to 54.8%, a sulfur content of 17.4% to 27.4%, and if all carbonaceous material is used, 47.9% carbon, if only charcoal is used, 17.8%.

[37] If both the inner ball and outer coating are considered for the third formula, that would yield a nitrate level of 27% if all carbonaceous matter was taken, 31.2% if this excluded poisons, and 51.7% if charcoal alone was used.

The Wujing Zongyao describes a flamethrower with a double-acting two-piston cylinder-pump capable of shooting a continuous blast of flame.

[44] The Chinese author Lin Yu explained in his book of 919 AD that Greek fire was acquired from their Arab maritime trade contacts in the Indian Ocean.

Inside the cylinder there is a (piston-)rod packed with silk floss, the head of which is wound round with hemp waste about ½ inches thick.

[45] Before use the tank is filled with rather more than three catties of the oil with a spoon through a filter; at the same time gunpowder (composition) is placed in the ignition chamber at the head.

[47]Then the text goes on to provide further instructions about equipment, maintenance, and repair of flamethrowers: When filling, use the bowl, the spoon and filter; for igniting there is the branding iron; for maintaining (or renewing) the fire there is the container.