King of German Mercenaries

Marin's worries became a reality. Through the information brought by some businessmen, he learned that the Frisian noble republic across the sea was very dissatisfied with Marin's aggressive recruitment of Frisian fishermen.

Most of the Friesian fishermen's harvest was handed over to the Friesian nobles. However, when Marin recruited them, he was directly robbing the interests of the Frisian nobles.

So, the parliament of the Frisian Aristocratic Republic of Groningen is discussing whether to teach Marin some lessons...

These Frisian nobles would not dare to kill Marin, as that would break the rules, offend the emperor, and give the emperor an excuse for annexation. However, it was no problem to send troops to attack the island of Texel, to snatch it, and to bring back those recruited Frisian fishermen, and no one would gossip. Because it was Marin who robbed the Frisian fishermen first.

Of course, Marin will not sit still, so he plans to strengthen the defense of Texel Island...

Although Texel Island is an island, it is quite special. Because this island is not accessible from all sides.

Mainly, two-thirds of the coast around Texel Island is a very shallow shallow sea area. Whenever the tide ebbs, two-thirds of the shallow sea around Texel Island turns into a silt-filled beach. After high tide, it turns into a shallow sea. Ships can easily run aground if they are sent to land in these areas. Small boats are okay, big boats must not be near the coast in these areas, or they will definitely run aground.

In the entire Texel Island, only the Mars channel in the southern sea area and the Odeshird area on the southeast coast belong to the area with sufficient water depth, suitable for larger ships to dock and also suitable for landing.

Therefore, to guard against the attack of the Frisian noble republic, it is enough to arm the coastal areas on the south and southeast of the island. Among them, the focus of the defense is on the two places of Tholencher and Odesschild and the nearby coast.

The most effective way to guard against the attack of the Frisian Aristocratic Republic is probably to build a fort. The turret can place heavy artillery, and the enemy ships attack.

Moreover, the fort is generally built of stone, and has a strong ability to resist iron balls. But ships are different. Today's ships, until the mid-19th century, had wooden hulls. The anti-strike ability of iron ball shells is very limited. The wooden warship and the coastal defense artillery in the stone fortress will definitely suffer. Moreover, the coastal defense artillery can be made very large and heavy, and it is very powerful. The artillery on wooden ships is often very limited and cannot be made too heavy. Otherwise, the small boat is equipped with a cannon, and the recoil of the cannon may overturn the wooden boat.

As a result, Marin immediately made the decision to build coastal defense forts in the ports of Thorrenche and Odesschild to guard against the possible attack of the Frisian Aristocratic Republic.

Texel Island does not have the ability to make guns, and there are no artillery craftsmen. At the end of the 15th century, gunsmiths were definitely the top talents in Europe. Even in those big countries, artisans who can cast guns are high-end talents. Marlin can easily recruit gunsmiths, but it is difficult to recruit gunsmiths. Therefore, he can only choose to buy guns.

To this end, Marin sent people and hired Jewish merchants to help them find out the source of the artillery...

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

In addition, France is also a country that attaches great importance to gun casting, and the casting technology is good. However, Marin lost a lot of face for letting Charles VIII. Therefore, it is impossible to buy guns with the French.

therefore,

Marin can only look to other countries - England, Portugal and Spain...

However, the feedback from the people who sent it back was not very good...

The feedback from the people sent to Spain and Portugal indicated that in Spain and Portugal, the most popular at present is the bronze rear-loading cannon - which is also known as the Fran cannon in the Ming Dynasty.

This kind of gun has a range of only 2,000 feet (666 meters, recorded in the Ming Dynasty), and it is absolutely inappropriate to be used as a coastal defense gun. Even if it is used as a naval gun, its power is a little too small.

However, because it has just entered the era of navigation, Europeans have not paid much attention to the power of naval guns. Therefore, it is reasonable to popularize such small-power bronze cannons. The development of European artillery technology was about the 16th century. Due to the needs of naval warfare, heavy artillery such as the "Hongyi Cannon" was developed.

Moreover, bronze artillery cannot be made too large at all. Because, bronze has a major flaw - it tends to soften after overheating.

Smaller caliber bronze guns are fine, but larger caliber ones are different. Large caliber artillery, high chamber pressure. When the barrel overheats, the gun wall softens. After overheating, bronze is not as soft as pure copper, but it softens after all. The bore pressure of small-caliber guns is not bad. Because of the high bore pressure of large-caliber guns, it is easy to deform the inner wall of the gun barrel when it is fired under the condition of overheating. In this case, the artillery is useless.

Therefore, bronze cannons cannot be cast too large, only medium and small ones. If you want to cast heavy artillery, you can only choose to cast artillery from iron. Moreover, the cost of cast iron guns is much lower than that of bronze guns. After all, before the development of the largest copper mine in Sweden and the acquisition of Japanese copper by the Dutch, the price of copper in Europe was still very expensive. Casting a heavy gun with a lot of copper is absolutely costly.

Marin was originally disappointed, but there was good news from the UK...

The personnel sent to Britain to buy guns were divided into several groups. The first few calls failed to bring good news. But the men sent to Sussex (or Sussex) in England brought back good news.

Sussex is located on the southeastern coast of the United Kingdom and has always been a developed area of ​​the United Kingdom and the center of British iron smelting. Since the casting of cast iron blocks in Dijon, France in the mid-15th century, this technology has gradually spread, and more than ten years ago, it was spread to Weld in Sussex, which is across the sea from France.

As a result, a gunsmith in Weld, Sussex, began to try to use cast iron to cast guns. Because, cast iron is much cheaper than bronze.

After more than ten years of attempts, the gunsmiths in Sussex used cast iron blocks to cast a cast iron Kofeilin long-barreled gun.

According to the description of the subordinates, this cast iron gun, which is still being tested, is a 12-pound gun. Originally, the old gunsmith Johnson wanted to forge the 18-pound Kofelin long-barreled gun. However, the cast iron technology of this era...

When the old Johnson Cast used the 18-pound caliber, the barrels were often blasted because of the quality of the steel. To this end, the old Johnson's nephew was also seriously injured and disabled. In desperation, the old Johnson had to reduce the caliber without reducing the overall weight, making the cast iron gun into a 12-pounder.

Old Johnson almost exhausted his wealth in order to develop this kind of front-loaded heavy cast iron gun. Right now, he has only made initial progress. Old Johnson's goal was to upgrade the cast iron gun to an 18-pounder. Then, using this unique technique, ask the king to claim the reward...

"The 18-pound Kou Feilin long-barreled cannon... Could it be... this is the legendary 'Hongyi Cannon'?" Marin was taken aback.

He remembered that, more than a century later, the first batch of Hongyi cannons sold by the Portuguese to Daming seemed to be 18-pound long-barreled Kofeilin long-barreled cannons salvaged from British shipwrecks. And this old gunsmith named Johnson may be one of the earliest developers of the Hongyi Cannon...

"Talent, don't let it go!"

So Marin ordered to send someone to Weld, Sussex, England, to recruit the old Johnson family to Texel Island to cast cannons for Marin.

Marin's men had already inquired about it, because the British "Red and White Rose War" still had the aftermath, and Henry VII was still struggling to clean up the domestic opposition. Therefore, he has not noticed the casting of the cannon. And Old Johnson was not the official and royal cannon caster of the kingdom, but a folk artisan who had worked with regular craftsmen to cast cannons. Moreover, the old Johnson's cast-iron gun was not finalized for production, nor was it recommended to the kingdom, let alone adopted and valued.

Therefore, old Johnson is still not considered a British national treasure gunsmith at present. Therefore, it is not difficult to recruit old Johnson, at least it will not be blocked by the British government.

Malin specially sent Den Burg Mayor Heidel Lerman to lead a team to Weld, Sussex, to secretly recruit the old Johnson family. After offering a "high salary" of 1 shilling a day to the young people of the old Johnson family (the average daily salary of craftsmen is only 3p), the cannon-casting family of Johnson moved to Texel Island as a whole and began to specialize in horses. Lin cast guns.

As for the troubles of the old Johnson's bombing problem, Marin actually has a solution for a long time. The blasting of the cast iron gun is nothing more than the pig iron used for casting the gun. There are too many impurities, such as sulfur and phosphorus, which cause the gun barrel to be brittle. Moreover, the carbon content of pig iron is too high, although the strength is high, the toughness is insufficient, and it is not suitable for casting guns. The ones that are really suitable for casting guns are actually wrought iron and medium and low carbon steel.

Although Marin is not professional about how to make steel, he has also learned a lot of theories from many time-travel novels. For example, he knew that an important secret of the early British iron guns not easy to blow up was the use of reverberatory furnaces for secondary refining of pig iron.

The so-called reverberatory furnace is a relatively closed furnace (including air inlet and outlet). After the pig iron and scrap iron are put into the furnace, the heat in the furnace cannot be dissipated due to the relatively closed space. After reaching the furnace top and furnace wall, it is reflected back to concentrate the iron material. After a few hours of refining, plus some slagging agent (the simplest slagging agent is quicklime, which can be used to remove sulfur and phosphorus). Then, after cleaning up the waste slag (the waste slag is usually floating on the molten iron because of its density problem, it can be removed), and then the wrought iron or steel is obtained (the carbon content needs to be controlled).

The famous steel-making open-hearth furnace is actually just adding a regenerator to the reverberatory furnace.

The British Empire completely 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. And because the French did not understand this technology, until the early 19th century, naval guns were still very easy to blow up. It was not until the mid-19th century that France and other European powers initially learned about the technology of reverberatory furnace refining. But then, the open hearth appeared, and mankind entered the age of open hearth steelmaking. And artillery has also entered the era of forging cannons from casting cannons.

(The so-called forging gun is to place the steel column under a large hydraulic press of several thousand tons or even tens of thousands of tons, and cold forge it under high pressure, so that the internal structure of the steel column is extremely compact and strong. Then, the forging A good steel column is drilled with a high-strength drill bit, and a barrel with a very strong and durable wall is obtained. For a cast gun, because the molecular structure of the gun body is relatively loose, the chamber pressure that can withstand is higher than that of forging of the same volume. The gun is much lower. Therefore, the barrels of the early cast guns are generally thick. The barrels of modern forged guns are relatively slender.)

Marin is not a steel major, but he has read a lot of related technical posts. He can't do it himself, but he will still instruct others to do it.

For example, this reverberatory furnace has a very simple structure. He could instruct the craftsmen to get one, and then get high-quality wrought iron and steel. Then, casting the gun with wrought iron or medium and low carbon steel is definitely much better than the cast iron gun with a lot of impurities in this era, and it is not easy to blow up.

Of course, the reverberatory furnace technology is an "advanced technology" that only appeared in the 18th century, so Marin can't reveal it casually. Therefore, he considered using serfs whose freedom was restricted to do this. Because the serfs could not leave their place of residence at will, and had no conditions to leak technology out. Even the life and death of the entire serf's family is in the hands of the lord, and the risk and cost of betrayal are enormous. Craftsmen recruited like Old Johnson are free in their identities. If someone else offered a high price, he might not be able to resist leaking the technology. Moreover, before the old Johnson came to Texel Island, he signed an agreement with Haider Lerman, stipulating that Texel Island should not restrict their personal freedom. In this regard, Marin must also abide by the contract. Otherwise, he would not be able to recruit more craftsmen.

Of course, those are later stories. The most important thing for Marin right now is to ask the Johnson family to help him cast some more 12-pound cast iron guns for coastal defense.

At present, 3-pounder guns, 4-pounder guns, 6-pounder guns, etc. are more popular in Europe. Artillery with more than 10 pounds is considered a heavy gun. Marin used a 12-pounder gun at the coastal fort, which was absolutely enough to suppress the warships of the Frisian Noble Republic.

Because, according to the information, the largest caliber artillery on several warships owned by the Frisian Aristocratic Republic is only a 6-pounder, and it is not a match for a 12-pounder at all.

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