In summer, the northern coast of Germany is rainy and cloudy. Pen ~ fun ~ Pavilion www.biquge.info Although it is not a heavy rain, the climate is humid and wet, which makes people feel uncomfortable.

The three important cities of Aurich, Emden and Lyell, the capital of the East Friesian Lamber, were replaced with cast-iron gates and rusted were discovered......

Because Marin used artillery + blasting when attacking Denmark, the pure oak city gates in Europe have become outdated. Therefore, the Danes were the first to introduce cast-iron gates in Copenhagen, which for a time left Marin's army helpless.

Back in East Friesland, Marin didn't want others to do the same with him. Therefore, the three most important cities in the territory of East Friesian Lamber were naturally the first to install cast-iron gates. Even, Emden's cast-iron city gate was simply demolished from Copenhagen and refitted.

Marin actually understands the shortcomings of the iron door, that is, it is easy to rust. Therefore, he had already arranged for his subordinates to paint the big iron gate to isolate the moisture.

However, the paints of this era, very original, are of poor quality. After a long time, after being exposed to the wind and sun, it is easy to lose the paint. After the paint is removed, the iron part is exposed. Then, if you come to the wind and rain or something, it will naturally rust......

Although this had been expected for a long time, Marin still had a great headache. A good big iron gate, if it breaks, the loss is very large. After all, blast furnace ironmaking is not yet popular in Europe, but some blacksmith shops are still using the original method of accumulating iron ore and charcoal in charcoal stoves. Therefore, the price of iron is very high.

In desperation, Marin had no choice but to order a repaint. However, now European paint is so expensive that it costs a lot to paint it several times.

Nowadays, there are no synthetic paints, all paints are extracted from lacquer trees and minerals, which are small in quantity and expensive. If you paint every once in a while, the cost is a bit high......

So, Marin thought of galvanizing......

Unfortunately, the Europeans have not yet extracted zinc. Marin knew that there was a Tara lead-zinc mine in the northwest of Dublin, Ireland, with huge reserves. It's a pity that the huge lead-zinc mine is right in the direct territory of the British king under the reign of Henry VII. With the treacherous character of Henry VII, would he allow himself to mine and smelt zinc?

You know, because of the profits and taxes of the woolen industry, Henry VII desperately suppressed wool exports and set up his own wool factory.

Therefore, if he knew that there was a huge lead-zinc mine in his index territory, even if he gave it to him before, with his scoundrel character, he would take it back. Not to mention anything else, a large lead mine alone was enough to make Henry VII turn his face shamelessly on his heels.

And if you tin the city gates, it is also a good choice. After all, tinplate is also rust-proof. However, tinplate has a fatal flaw - once the tin plating is worn out, it will soon spread rust around the wear point.

And the bump and bump of the city gate is inevitable. Therefore, it will also be problematic to solve it by tin plating. The best solution is galvanizing.

In fact, if you want to prevent shelling, you don't need to use pure cast iron gates, and it is enough to cover the outside of the gates with thick iron sheets or iron plates.

After all, it is very difficult for a mere iron ball cannonball to smash open a city gate covered with thick iron sheets or iron plates. The reason why Marin replaced the three cities with pure iron cast-iron gates was that the Danes brought them into the ditch.

Later, during the test, Marin found that the use of a rear iron sheet or iron plate thicker than the ordinary iron sheet to cover the oak gate could also resist shelling. Moreover, there is another advantage that cast-iron gates do not have - that is, they are easy to replace.

The pure cast iron gates used in Marin and Denmark, Hamburg, Lübeck and other cities are now rusted and damaged, it will be miserable, and the entire gate will be useless and need to be replaced as a whole.

And if you use the method of nailing thick iron sheets or iron plates, even if a thick iron sheet or iron plate is broken, it is just to take down the rusted iron plate and replace it with a new one.

It's just that whether it's a thick iron sheet or an iron plate, it has the same disadvantage as a cast iron gate - it's easy to rust......

Before, it was not that there were no European cities that had covered the city gates, but in the end, they all chose to give up because of the problem of rust.

At the same time, China and other parts of East Asia used the method of thick copper skin to enhance the fortification of the city gates. However, that is the East Asian region. In East Asia, a tael of silver can be exchanged for 1,000 copper coins or more. In Europe, a silver coin can only be exchanged for 15 copper coins of the same size. Therefore, from the cost point of view, the average country does not have the economic strength at all, and the city gate is covered with copper.

Even if it is a local tyrant like Marin, it is okay to cover the four gates of the capital Aurich, and cover the gates of other cities? Forget it......

15 Fast iron is equivalent to a piece of silver skin of the same size, who can be so extravagant to make several city gates in various cities covered with copper skin?

Therefore, after thinking about it, it is the most economical and effective way to cover the oak gate with galvanized white iron sheet. Now the only question is - where does the zinc come from?

As a result, Marin had to set his sights on the Tara lead-zinc mine in Ireland......

Although, the Tara mine is in the territory of the old fox of Henry VII. However, the island of Ireland was not dominated by Henry VII's family at this time......

You know, Marin helped Earl Edward of the York family to go to the island of Ireland, and also took control of Cork, the first port on the island of Ireland. Not only that, but Count Edward also had 5,000 mercenaries by his side......

After much thought, Marin decided to start supporting Earl Edward and let him make trouble on the island of Ireland. Even, support Earl Edward's unification of the island of Ireland.

After Earl Edward had taken possession of Dublin and its environs, the only direct territory of England on the island of Ireland, Marin could have bought the Tara Mine from Earl Edward, in the name of the North Sea Chamber of Commerce, which had saved his life. Then, the excavated lead-zinc ore is pulled elsewhere to refine the zinc......

The financial strength of the Earl of Edward was far from that of Henry VII, who controlled England. Therefore, after the Earl of Edward occupied the direct territory of the British crown near Dublin, he must have needed funds to prepare for the war against the counterattack of Henry VII. Therefore, Edward at that time must have been very short of money. When the time comes, in the name of the Beihai Chamber of Commerce, you will not have to worry about not being able to buy this Europe's No. 1 lead-zinc mine......