Chapter 14 Cannon and Gunpowder Formula

In winter, the peasants were idle. The year passed. (How could they be idle?)

Many peasants came to Constanta, Tulcea, Mangalia and other places to find work and earn some money to support their families.

The Lord of Dobruja also had many construction projects, and buildings such as docks, city walls, and churches were being built or expanded. In addition, the army had been recruited, and a total of 7,000 peasants were called up for training. Their families also farmed and spun in Constanta, which also boosted the prosperity of Constanta invisibly.

Most of the newly recruited soldiers were serfs and mountain people. Although they had little knowledge, they were relatively simple and obedient. They were simple in heart, without the little tricks of the city people, and were the easiest to fool. These people, as long as they were trained and fooled, would definitely be a powerful military force.

At the same time in Constanta, Peter also built several coastal defense guns. The forts were generally built of stone, and had strong resistance to iron ball shells. But ships were different. The current ships, until the mid-19th century, were all wooden hulls. The ability to resist the impact of iron ball shells is very limited. The wooden warships and the coastal defense guns in the stone fortresses will definitely suffer. Moreover, the coastal defense guns can be made very large and heavy, and they are very powerful. The guns on wooden ships are often subject to great restrictions and cannot be made too heavy. Otherwise, if a small boat is equipped with a cannon, the recoil of the cannon may overturn the wooden boat.

Wallachia has no ability to make cannons, nor does it have cannon-making craftsmen. Now it is still the end of the 14th century, and cannon-casting craftsmen are definitely the top talents in Europe. Even in those big countries, craftsmen who can cast cannons are high-end talents. It is difficult for Peter to recruit cannon-casting craftsmen. Therefore, he can only choose to buy cannons.

After inquiring, Peter learned that the Holy Roman Empire's cannon-casting level was very average, and it could only cast small bronze cannons for land warfare. This is because the Holy Roman Empire is a land-based country. Moreover, the southern part of the empire is close to the Alps, and the cannons need to be portable and able to cross the Alps. Therefore, the cannons cannot be cast very large. The artillery required for the coastal defense fort must be heavy artillery. Therefore, the artillery of the Holy Roman Empire obviously does not meet the requirements.

However, because it has not yet entered the Age of Navigation, Europeans do not pay much attention to the power of naval guns. Therefore, it is reasonable that this kind of small-power bronze cannon is popular. The development of European artillery technology was around the 16th century. Because of the needs of naval warfare, heavy artillery such as the "Red Cannon" was developed.

Moreover, bronze cannons cannot be made with too large a caliber. Because bronze has a major defect-it is easy to soften after overheating.

Bronze cannons with smaller calibers are okay, but large caliber ones are different. Large-caliber cannons have high chamber pressure. When the barrel is overheated, the gun wall becomes soft. Although bronze is not as soft as pure copper after overheating, it softens after all. The chamber pressure of small calibers is okay, but large-caliber cannons are easy to deform the inner wall of the barrel when fired under overheating because of the high chamber pressure. In this case, the cannon is useless.

Therefore, bronze cannons cannot be cast too large, only small and medium-sized ones can be cast. If you want to cast heavy artillery, you can only choose to cast artillery with iron. Moreover, cast iron artillery is much cheaper than bronze artillery. After all, before the development of the Swedish copper mine and the Dutch obtained Japanese copper, the price of copper in Europe was still very expensive. The cost of casting heavy artillery with a large amount of copper is absolutely high.

Peter originally thought that the artillery had to be developed slowly, but the troops who went to the Golden Horde brought back good news.

From the 13th to the 14th century, trade between Europe and China was mainly conducted through the Golden Horde. Therefore, the Mongolian rulers attached great importance to the development of commerce. Batu Khan and Berke Khan successively built the cities of Batu Sarai and Berke Sarai on the Volga River, and later built the city of Uvik, and built the city of Sarachik at the mouth of the Sayahei River (Ural River).

As a bridge for trade between the East and the West, the Golden Horde naturally also had a group of craftsmen traveling from north to south. Among them, a craftsman from the Central Asia region actually made a cannon with iron.

The appearance of cast iron cannons had to wait until the mid-15th century. After Dijon, France, made cast iron blocks, this technology gradually spread and later spread to Weald, Sussex, across the sea from France. So the cannon casting craftsmen in Weald, Sussex, began to try to use cast iron to cast cannons. Because cast iron is much cheaper than bronze.

This Samarkand craftsman named Shavkat was dedicated to the construction of cast iron cannons, but they all failed. After finally making one, it burst. In order to develop this front-loading heavy cast iron cannon, he almost exhausted his family wealth. He even considered giving up completely, but people from the Dobruja region heard about him and found him to ask if he was willing to meet their lord.

He thought that instead of waiting like this, it would be better to take the initiative. Maybe this lord has a long-term vision.

He was right. Peter was a long-term visionary. After hearing about his work and experience, Peter thought: "This is a talent that must not be missed!"

So he immediately decided to hire this craftsman and offered a salary of 1 British shilling per day (the daily income of ordinary people was 3 pence).

As for the problem of barrel bursting, Peter also has a solution. The barrel bursting of cast iron cannons is nothing more than the pig iron used for casting cannons, which has too many impurities, such as sulfur and phosphorus, making the cannon barrel brittle. Moreover, pig iron has too high carbon content. Although it has high strength, it lacks toughness and is not very suitable for casting cannons. In fact, wrought iron and medium and low carbon steel are really suitable for casting cannons.

Although he is not an expert in steelmaking, he has learned a lot of theories from many time-travel novels. For example, he knows that an important secret of the early British iron cannons is that they used a reverberatory furnace to refine pig iron twice.

The so-called reverberatory furnace is a relatively closed furnace (including air inlet and outlet). After putting pig iron and scrap iron into the furnace, the heat in the furnace cannot dissipate due to the relatively closed space. After reaching the top and wall of the furnace, it is reflected back to concentrate on refining the iron. After several hours of refining, some slag-forming agents are added (the simplest slag-forming agent is quicklime, which can be used to remove sulfur and phosphorus). Then, after cleaning up the waste slag (due to density problems, the waste slag usually floats on the molten iron, so it can be removed), wrought iron or steel is obtained (the carbon content needs to be controlled).

The famous steelmaking flat furnace is actually just a regenerator in the reverberatory furnace.

The British Empire had fully mastered the reverberatory furnace refining technology in the 18th century, which also made the iron cannons cast by the British of high quality and not easy to explode. However, because the French did not understand this technology, the naval guns were still very easy to explode until the early 19th century. It was not until the mid-19th century that France and other European powers initially learned about the reverberatory furnace refining technology. But then, the open hearth appeared, and mankind entered the open hearth steelmaking era. And the cannons also entered the forging era from casting cannons.

Although Peter was not a graduate of the steel industry, he could command people to make it. As for this reverberatory furnace, the structure was very simple. He could completely command the craftsmen to make one, and then make high-quality wrought iron and steel. Then, using wrought iron or medium and low carbon steel to cast cannons would definitely be much better and not easy to explode.

As for gunpowder, Peter also had a way. He remembered a local method that the old man in the village used to say: find a vacant land, clean out impurities such as stones, and then dig a series of pits or simply use a cellar, and then pour water and lime into it to keep the temperature. In this way, after a period of "insulation", the soil becomes a saltpeter field.

Pour the collected urine of people and livestock into the pit. After about ten months, the soil in the pit will be rich in saltpeter. Dig out this saltpeter-rich saltpeter soil, then add plant ash for filtration. After that, you only need to boil saltpeter water to get high-quality saltpeter.

With saltpeter soil, it is more convenient to make gunpowder. At this time, the gunpowder formula used by European countries is: 50% saltpeter, 25% sulfur, and 25% charcoal. It is more likely to explode and belongs to the formula of explosive firearms. And the gunpowder made in this way is still in powder form, and many situations will occur in the use of such gunpowder. For example, powdered black powder is easily squeezed together when it is stressed in the barrel, so it cannot be completely burned due to lack of oxygen when ignited, which reduces the power of the gunpowder.

Another disadvantage of powdered gunpowder is that it is easy to get damp. This is because in order to increase the production of potassium nitrate, Europeans at that time often sprinkled a lot of lime powder in the saltpeter field. Although this operation can increase the production of potassium nitrate, it also greatly increases the calcium nitrate contained in it. Calcium nitrate has a strong hygroscopicity, which makes saltpeter easy to deliquesce, making gunpowder unable to be used normally unless it is exposed to the sun before use.

In addition, the transportation of powdered gunpowder is also inconvenient, because during the bumpy transportation of powdered gunpowder, sulfur powder, charcoal powder and saltpeter powder with different weights will separate from each other. The saltpeter powder with the highest density will be at the bottom of the gunpowder barrel, and the lightest charcoal powder will be on the surface of the gunpowder barrel, which will inevitably reduce the power of the gunpowder, or even make it impossible to ignite! Before use, unless all the gunpowder is poured out and remixed, there is still time to operate when the war is not urgent, but once an urgent war occurs, it cannot be quickly used.

Therefore, in order to maximize the power of gunpowder, the production of granular gunpowder must begin.

In fact, granular gunpowder is also very simple to make. Just add flour, compact it, add water, and then break it. And Peter's gunpowder formula is close to the ideal ratio (75% saltpeter, 12% sulfur, 13% charcoal).