The watchmaker departed and set out on his way back to Sardinia with the thoughts in his heart.

Ferdinand and Juana were also leaving, boarding the ship to the New World.

Ferdinand is entitled to be proud of what he has achieved over the past 20 months: in the field of cotton weaving alone, weaving speed would have increased by 160 times and weaving speed by hundreds of times if his latest results had been adopted. Of course, the actual situation is not so good, and the dependence on water and manpower limits the development of the productivity of the cotton textile industry, but the efficiency is increased by more than ten times, which can definitely be achieved.

Of course, the six key inventions – three spinning machines, two looms and flintlock pistols – are not yet widespread, and there is a tendency to tighten secrecy, with new technologies and new factories concentrated in Sardinia. At the moment this is a must-do, and although he doesn't think secrets are so easy to leak, he himself is about to leave for more than two years. A lot can happen in more than two years.

So he had to be cautious and focus on the development of Sardinia first, to see if more than three years of construction could turn this small world upside down.

Of course, Ferdinand's tech tree was not entirely concentrated in the field of cotton textiles, nor did he only develop flintlock pistols and line guns in the military field, but he also focused on an industry that would become very important in the future.

Iron and steel industry.

For three-quarters of a century, from the time of the Franco-Prussian War to the rise of the mushroom cloud over Hiroshima, a country's steel production, along with coal, oil, and electricity, directly determined a country's strength, strategic pattern, and war situation on paper. The long war of attrition is the collision of steel. The results are often determined by the data on paper.

Although the focus of the first industrial revolution was light industry such as cotton textiles, the steel industry also made an important paving and promotion for the industrial revolution, and eventually became the most powerful data on the report card of the industrial revolution.

Ferdinand attached great importance to smelting steel, and the current European smelting technology at the end of the 15th century was frighteningly low, and it was not until 1709 that he mastered coke iron-smelting technology, which directly contributed to the Industrial Revolution.

Since 1709, Europe has used modern blast furnaces, and due to the serious destruction of forest resources, the carbon-based iron-making method has been adopted, which has greatly promoted the improvement and efficiency of iron production.

Ferdinand experimented with blast furnace ironmaking in Sardinia, using a modern blast furnace without a slag outlet. As for coke, because he doesn't have much time, he can only use the soil method for coking for the time being, and then build a modern coke oven in the future.

When it comes to smelting steel, one of the big problems for Sardinia and for Spain as a whole is the lack of coal and iron. The main reason is the lack of high-quality iron, and there is only a small number of high-quality iron ore in Spain and even in southern Europe.

If iron is not good, steel is not good, and if steel is not good, guns are not good, so Britain has a lot of coal and iron, and the guns are of high quality and powerful, which has laid a good foundation for establishing military superiority and developing the industrial revolution. Oil was a bit of a problem in World War II, but today there are North Sea oil fields, and together with Norway, it is one of the few developed countries in Europe that is self-sufficient in oil.

Now it shows the superiority of Ferdinand's status, with the power of the king, he can mobilize and control the best iron ore resources in Spain to supply Sardinia, and the scale of iron and steel making in the initial stage of a Sardinia island is more than enough to meet the needs. Later, the scale developed, and iron ore resources could be obtained from the United Kingdom and the Americas. Of course, even if the Americas are forgotten, it is better to develop and build them directly.

In addition to large-scale blast furnace ironmaking, Ferdinand also applied the crucible steelmaking method of 1742, which was used for small-scale tapping. This is a method of melting metal into molten steel in a graphite clay crucible. In 1742, it was first applied by the Englishman Hunzman, who cut the carburized iron into small pieces and placed them in a closed clay crucible, heated outside the crucible, and the iron continued to absorb the carbon in the graphite and melted into high-carbon molten steel, which was cast into small ingots and then forged into the desired shape. When the steel is melted in a crucible, graphitic carbon can also act as a reducing agent, and the following reduction reactions occur:

C+FeO=CO+Fe

2C+SiO2=2CO+Si

Oxygen can be removed from the steel, and various inclusions can also be removed from the liquid steel, so the quality of steel (tool steel) is superior to that of various metal materials at that time, and it can be used to make tools for processing metal materials. The crucible method was the first method of producing liquid steel in human history. However, the production volume is extremely small and the cost is high.

Of course, at the level of the late 15th and early 16th centuries, it was already very advanced technology.

At the same time, in order to solve the problem of unexcluded impurities, limestone and iron ore with higher purity are added to remove sulfur, phosphorus, silicon and copper before putting in graphite. The specific reaction is as follows: CaO+S+C=CaS+CO,

10P+5Fe2O3=5Fe+5P2O5，

3CaO+P2O5=Ca3(PO4)2，

Cu and Si underwent redox reactions with two oxidants, and the above products surfaced on the surface of molten iron.

By controlling the amount of graphite, the carbon content of the steel can be regulated: if the amount is large, it is high-carbon steel, and if it is small, it is medium and low-carbon steel.

High-carbon steel is strong and harder, making swords and armor. Medium and low carbon steels are used to make gun barrels.

However, due to the distance of the Americas and the lack of related resources in Spain - iron ore and coal, it is inevitable to import coal and iron ore from England.

For the next forty years, the British will take advantage.

But forty years later......

Well, the Supreme Act was issued in 1534! Henry VIII did his own thing, whether to divorce Catherine or to prevent Spain from taking the throne of England.

If it is the former, then it is the father's responsibility to teach the responsible man a lesson.

If it's the latter, then it's even more incredible.

Of course, even if Henry was honest, Ferdinand would have conquered England. In the long run, it leveled the European-stirring sticks, eradicated the mantis that stood in the way of Spanish hegemony, and gained a base and vassals on the western flank of Europe.

In the short term, a large amount of cheap coal and iron resources can be plundered.

In addition, after England is controlled, it can act as a mouthpiece and spokesperson for Spain.

The Italian wars were fought for decades, and after 1516, Ferdinand took control of Navarre, a Spanish territory, and established his rule over Naples, he would no longer care about the affairs of the region. In addition to maintaining territorial sovereignty that is not negotiable, he is reluctant to meddle in the affairs of the Apennines and the European continent.

However, the HRE Emperor was his natural ally, and he could not let France sit calmly in Italy, and in terms of the German Protestant princes, without the containment and help of Spain, it is estimated that the HRE Emperor would be in danger.

But Spain can provide financial support, diplomatic support, and even mercenaries, volunteers, and it is really difficult for you to get Spain to directly participate in the war.

Participation in a large-scale continental war was not something he should have done in his lifetime. By the time the Thirty Years' War was in full swing, the European continent was naturally Spain's possession. Moreover, the war between the Japanese and the Ming and Qing dynasties were also in the same era, which was a good opportunity for Spain to sweep the world.

But you can't get Spain to completely deny direct military support to HRE.

Then let England do these things.