Making black powder doesn’t require too many ingredients. But the history of gunpowder, and of making powder that could be used in artillery, is rather complex and fascinating. I had to do a fair amount of research into the subject for the Colplatschki books, in part because I had no idea exactly when the shift from match-lock to flint-lock took place, and when cannons first became important. As usually happens to me, it just grew from there. Because you can’t have firearms without chemical propellant. Torsion weapons, yes, but not guns. And it turns out that black powder has a fascinating history and was the cause of a lot of headaches for would-be gunners. It was also part of why firearms and crossbows and other “out-of-date” weapons existed side-by-side for so long.
Sulfur is easy to find. Charcoal is very easy to make. Saltpeter is . . . more difficult.
The whole basic idea of a firearm, cannon, pistol, what-have-you, is that expanding gasses propel a projectile at a target. Steam might work, and compressing air then releasing it might also work (and does. As the squirrels and grackles at Redquarters know.) But steam has several draw backs, including needing to transport a lot of fuel and water, and the propensity of steam to blow things apart (not that black powder was much better at first.)
The Chinese invented gunpowder by accident while looking for other things, namely immortality. The powder made sound very much like the bits of bamboo when tossed onto a fire, and was used first as a noise maker, then for fireworks, and then in rockets and simple, low-powered cannons. And that was where the Chinese stopped, for reasons still being debated among historians today. When Europeans were introduced to black powder, they used it for similar things, although scaring away predatory animals was not very high on the list. Europeans also decided that while the small cannon-like rock throwers were not bad, something larger was needed. And because Europeans had experience casting larger, hollow metal things in the form of church bells, artillery as we know it was born, tossing stone balls with eventually the same force as a good ballista or trebuchet. The metal held the projectile and the gas-making powder, someone added fire to the powder, and then once enough pressure built up, the stone ball departed out the open end of the cannon. When all went well, that was. If the casting was flawed, or the metal weak, or the charge of powder too large, or fire went in the wrong place, the cannon might blow up. If it were humid, or the powder had been made wrong, nothing would happen at all.
When it came to making black powder, Europeans had a severe disadvantage over China and India. Saltpeter does not “grow” as well in Europe because it is too cool and damp. The ideal saltpeter is potassium nitrate. When combined in the right proportions with sulfur and charcoal, and heated, it has a chemical reaction that produces its own oxygen, quickly. That burst of hot gas is the power that drives the bullet or ball down the barrel. Because potassium nitrate was hard to get in Europe in the quantities wanted, people improvised with sodium nitrate, often contaminated with calcium nitrate. It produced a weaker powder that was hygroscopic, meaning that it pulled water in from the air. Black powder as made in the early Renaissance went bad very quickly, and gunners would have to bake and re-grind the powder to make it work. You blended the three components by grinding them together. If anything spark-like happened, the mass exploded. For this reason, powder mills were soon restricted to outside city walls.
In order to obtain saltpeter, monarchs and others instituted rules allowing petermen (those tasked with collecting the raw materials) to poke around barns, outhouses, and other places where urine and dung collected and sat. The ordure, collected and slightly processed, was then processed further to produce the desired nitrates, a smelly business that led to the work being chased outside the city walls, far away. It also caused peasants to resent the petermen for upsetting their farms and for enforcing royal orders to leave barns dirt-floored (to encourage crystal growth) instead of allowing stone floors that were easier to clean.
Because of the sulfur, associated with the devil, people assumed that something infernal happened with the mix, or that Old Scratch himself had inspired it. Gunners and powder makers fell under the same suspicion, and several times the Church tried to ban powder and firearms, (along with crossbows) as cruel and evil weapons. Some lords maimed captured gunners for daring to fire at the nobility.
Firearms, aside from cannon, did not replace older weapons until the 1600s. Crossbows remained deadly, and muskets were cumbersome and clumsy, slow to load and touchy to fire, even after flint-locks replaced match locks.
I think you can see a few of the problems with this system. Fight in the rain? Nope. Ever-lit match around two kinds of powder that are being loaded by a lot of people standing in close proximity? Could be exciting. If the powder in the pan lit but the flame did not make it into the gun, it was a flash in the pan.
The flintlock was much better, at least in terms of not having to have open flames around powder.
How coarse or fine ground the powder was affected how it burned. This in turn meant a stronger or weaker “umpf” to the powder. Cannon powder was more coarsely ground, making it more powerful because of the rate flame spread and the amount of oxygen available between the pieces and then liberated by the chemical reaction within the burning stuff. The right grind could allow someone to use less powder with the same effect, a topic that comes up several times in Elizabeth and Empire. Cannon powder and musket powder were not interchangeable, neither were pan powder and barrel powder for muskets. In fact, The Imperials and Sea Republics could not share powder because the Imperials’ stronger, coarser powder would have blown up the Sea Republic guns.
Bad castings, bad loading, overuse, and bad luck could also cause cannon to blow their breeches (if one was lucky) or explode entirely. The scene in Blackbird when the Turkowi cannon exploded and took out several more is based on an actual Renaissance event. It also happened on Royal Navy ships (and others) if someone failed to properly swab out the barrel with a wet swab, cooling the metal and removing any lingering burning bits. If someone got careless or the gunners ran out of water . . .
The saltpeter problem is going to return in the next Colplatschki books, especially the one after Forcing the Spring. NovRodi can’t keep importing saltpeter and gunpowder forever, especially once Frankonia turns its sights west . . .