Wujing Zongyao - Gunpowder Formulas and Weapons

Gunpowder Formulas and Weapons

Gunpowder warfare began in China during the early 10th century, with the advent of the black-powder-impregnated fuse that was used to light the burst of the Chinese two-piston flamethrower. However, despite circumstantial evidence to the invention of gunpowder as early as the 3rd–4th century BC by the alchemist Ge Hong, it was not until the Wujing Zongyao that the exact formulas for early Chinese black powder was revealed. In the Wujing Zongyao there are three formulas for black powder provided, including one for an explosive bomb launched from a trebuchet catapult, another for a similar bomb with hooks attached so that it could latch on to any wooden structure and set it on fire, and another formula specified for a poison-smoke bomb used for chemical warfare. The Wujing Zongyao stated that simple incendiary weapons were launched from catapults, thrown down from city walls at besiegers, or let down by iron chains from a swape lever set up on the top of the wall. There was also description of the 'igniter ball' used in warfare and in finding firing range. The Wujing Zongyao stated the following:

The 'igniter ball' (yin huo qiu) is made of paper round like a ball, inside which is put between three and five pounds of powdered bricks. 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. When you want to find the range of anything, shoot off this fire-ball first, then other incendiary balls can follow.

The Wujing Zongyao's first recorded black-powder formula used in these bombs held a potassium nitrate level of 55.4% to 55.5%, sulfur content of 19.4% to 26.5%, and carbonaceous content of 23% to 25.2%. For the second labeled formula, the inner ball alone had a nitrate percentage of 61.5% to 50.2%, a sulfur content of 30.8% to 25.1%, and if all carbonaceous matter was taken, 24.7%, if just taking the charcoal content alone, the carbon level was 7.7%. 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%. If the inner ball of the third black-powder formula is only considered, it held nitrate levels of 39.6% if all carbonaceous matter was taken, 49.4% nitrate if excluding the poisons, and 60% if charcoal is specified alone. The sulfur content was 19.8% if all carbonaceous matter was considered, 24.7% if this excluded poisons, and 30% if charcoal is specified alone. The carbon content was 40.5% if all carbonaceous matter was considered, 25.9% if this excluded poisons, and 10% if charcoal alone was specified. 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 sulfur content would be 13.5% if all carbonaceous matter was taken, 15.6% if this excluded the poisons, and 25.9% if only charcoal alone was specified. The carbon content was 59.5% if all carbonaceous matter was taken into account, 53.2% if this excluded poisons, and 22.4% if charcoal alone was specified.

The first black-powder concoction was simply labeled as the "method for making the fire-chemical", with its ingredients and measured weight (in ounces) of each ingredient listed in the section below with the others listed in similar fashion.