At the top of the list of World Heritage Sites, as we all know, is Italy.

18 January 1493, Barcelona, Royal Palace.

Ferdinand is not talking about things like the Leaning Tower of Pisa in Italy, but about a material that was used in Rome in construction, cement......

Volcanic ash, this thing is not something that terrestrial creatures can endure. The world's largest human contact with volcanic ash began 74,000 years ago when Mount Toba in Sumatra erupted. At one point, there were only a few thousand late Homo sapiens left in the world.

All wars are civil wars, because all human beings are compatriots.

"That's enough, now let's click on the tech tree...... How can there be no strong fortifications for the things that kill each other...... The people's lives should also be improved! So it's time to inherit the legacy of ancient Rome – cement! ”

Also thanks to a certain novel, Ferdinand was now able to develop two kinds of pozzolana cement and Portland cement, the more high-end, refusal of service, now in 1493.

The ancient Romans used a mixture of limestone and volcanic ash in their construction very early, and it was already similar to modern limestone and volcanic cement. This type of cement is effective against fresh water and salt water, but it is not resistant to drying. The cement of ancient Rome has been named Roman cement.

This type of cement can be used in the construction of harbors and perhaps the hull of ships as appropriate, but it is not resistant to drying, so it cannot be used to construct buildings on land.

The classic version that can be used for land buildings in modern times is Portland cement, and the "ordinary Portland cement" is used in more than ninety percent of buildings and roads, which is common.

Concrete and steel made it possible to build almost the strongest fortress of this era. Even without rebar, it's just as powerful. The Mannerheim Line, supported by concrete fortifications, saved Finland in the Soviet-Finnish War. In the end, the Soviet army used large-caliber artillery to shoot directly, and only broke through the defense line with the crushing advantage of the artillery despite the heavy casualties of the artillery.

In 1813, the French engineer Francis Picker concluded that lime and clay were best mixed in a ratio of three to one, and his conclusion could now be borrowed 320 years earlier.

As for Roman cement, which is a mixture of limestone and pozzolana, the ratio is probably about 5 to 2 because the ash still contains less silicon than clay.

Sardinia has clay and Sicily has volcanic ash, and both are the private property and wealth of the king of Aragon, which is a perfect match.

Then give the order to Isaac Abravanel, first prepare Portland cement, and then order the volcanic ash to be transported from Sicily, without even purchasing, because the upper king of Sicily has the most lands. Speaking of volcanic ash, there may not be any need to place an order now. The king's power is used in the allocation of resources, and it is very efficient.

The Renaissance wave is in full swing, the Divine Comedy has been completed, the Mona Lisa has not yet been created, and since the Greco-Roman culture is to be revived, even the building materials should be revived. Even if other countries knew, they wouldn't necessarily take it seriously. Even if it is imitated, the proportions are not known, and the ash is concentrated in Italy. Even if it is really made in the right proportions, the pozzolana cement cannot be used on land anyway.

As for Portland cement, it is a product that is 320 years ahead of the times, as long as you keep it secret, no one can make any piracy, and when they succeed in piracy, the daylily will be cold.

Since there is bauxite in Sardinia, then more cement products can be developed in the future, but don't think too much about it now, otherwise you won't be able to get anything.

If Sardinia had taken the lead in making a large amount of cement and arming the entire island into a large cement fortress system, Ferdinand could have said that it was the fortress of Gibraltar in this era, and 300,000 people fighting 10,000 people might not be able to attack it, provided that a country could carry out such a large-scale landing operation. In the future, Spain must have this ability, and England's situation in North America is still far away, and now is the right time to prepare for a rainy day.

"Your Majesty ordered the massive mining of clay and limestone to make a solid building material from the ancient Roman era...... A month later, a large amount of ash will arrive at the port of Bosa and will be used to make another similar material. "Isaac Abravanel was a little embarrassed after reading the king's order, the Sardinians were obedient, the nobles were suppressed into submission, the title of chief prime minister was not given in vain, even in the puppet kingdom, it shows that no one on this island can resist his will!

"If the short-term employment is not enough, the 2,000 garrisons on the island can be used appropriately, and of course, the treatment should be improved......" The king's suggestion is very effective, but the financial expenditure is going to be expanded, but the financial advisers for many years have their own methods, and the nobles on the island who hide their personal interests cannot escape his discerning eyes.

The development of Sardinia is only a small matter, but the development of the American continent is a big project. If the east coast of North America and its roads to the Mississippi River basin had been paved with cement at the beginning of the 16th century, and if there had been a concrete road from Cologne to Panama City, it would have greatly increased the speed of development of the Americas and the control of Spain over the new territories. In the era when there were no Grand Canals, roads and railways, the cement roads on the New World were simply a smooth road after stepping on the 9981st difficulty.

Of course, Iberian properness is certainly the most important. Ferdinand had ambitious plans to build a rapid transit network in the Iberian Peninsula. In this era, no one is fully aware of the importance of transportation networks in military and people's livelihoods. Britain has only 130,000 land forces, and today the United States has only 500,000 land forces, and it is thanks to its unparalleled global strategic projection capability.

For the sake of initial secrecy and the acquisition of mature technology, starting in 1496, with Madrid (which was not the capital at that time), the cement road transportation network was established throughout Spain within 10 years, which would greatly save labor costs, facilitate the flow of goods and resources, and greatly accelerate the movement of Spanish troops to the Pyrenees and the Spanish-Portuguese border. After 1506, the vanguard of the Spanish cavalry in two or three days, the infantry in no more than ten days, can assemble from the interior to the inner side of the border, after the annexation of Portugal, it will strengthen Spain's effective control over the regions in Portugal, the road network through the whole peninsula, will make the historical aristocracy in Lisbon capture the royal palace uprising, can lead to the seizure of a large area of the surrounding territory no longer exists, and finally digest and integrate Portugal.

Soon the Kingdom of Sicily set off a large-scale volcanic ash boom, the king's domain was large-scale collection and mining of volcanic ash, the islanders were also full of enthusiasm, seeing that it was profitable, and the nobles also sold a large amount of volcanic ash to the royal family.

In Sardinia, the mining of clay and limestone has increased significantly. At the same time, several vertical kilns were built in the western port town of Bosa, and then more, where clay, limestone and volcanic ash converged in a delicate physical and chemical process.

Inadvertently, it seems that a small dirt road leading to the vertical kiln was the first to be paved with cement.