Such a simple powder has such an effect, which is very incredible, defense is the strongest place in the Northern Song Dynasty, and in order to defend, the Northern Song Dynasty has considered it from all aspects. Pen % fun % Pavilion www.biquge.info

Sun Ji even knew that in order to improve the strength of the city defense, even iron had been considered for application to the city defense, but because of the huge cost, it was finally stopped.

The specific gravity of iron is too heavy, and if you want to hold the entire city wall, it costs too much, which is not only too expensive, but also basically there is no way to implement, and it is impossible to put the iron of the whole country together.

You know, the iron-clad city wall, it is impossible to be thin, and it is even more impossible to be thick, according to a city wall is 8 meters high, the circumference is 3 kilometers, and the thickness of the iron sheet is 1 centimeter, which is already the limit, and iron is not omnipotent, one centimeter of iron, at most, is to resist the arrows, and it is impossible to resist the attacks of catapults and ballistas.

In the era of battleships, the protection of battleships often exceeded 300, or even 500 mm, which was invulnerable.

Even if it is one centimeter of iron, it will eventually surround a 3-kilometer-long one, and the iron consumed will reach 240 cubic meters, which represents 1,780 tons of iron, and if this thickness reaches 10 centimeters, it is 17,800 tons, which almost represents the annual output of the Northern Song Dynasty.

As strong as metal, this is always a beautiful wish, even in later generations, China is already the world's largest steel producer, the annual steel output, in the era of hundreds of millions of calculations, steel city, is still a luxury, after all, the proportion of steel is very large, a cubic meter of iron, the proportion of about 7.8, that is, 100 million tons of steel, at most is about 13 million cubic meters of steel.

13 million cubic meters, what does it mean, a kilometer long, a kilometer wide, 10 meters high building, his total volume, it is more than 13 million cubic meters, how big is a city, Beijing and Shanghai such a super city, the total area of more than 6,300 square kilometers, tiling 1 meter high steel, it is more than 6,300 cubic meters, not to mention other cities.

Iron and steel cities, can only be produced in a small part, this is still the premise of the large-scale liberation of the productive forces in later generations, in the productive forces have not been liberated, the industrial revolution has not been opened, the production of steel, more rely on the premise of manual work, with steel to cover the periphery of the city, increase the city's defense, that is just a fantasy thing.

Zhao Xin knew what Sun Ji was thinking in his heart, and he would definitely laugh dumbly, for example, on the battleship, the original wooden-hulled ironclad ship used hundreds of thousands of tons of iron, which was difficult for the industrial society to bear, let alone the Northern Song Dynasty.

In the whole north, how many cities are strategically important, not to mention one or two hundred, if these cities are all wrapped in iron, it may be possible for the Northern Song Dynasty to produce for hundreds of years, but now it is simply impossible.

The annual iron production in the Northern Song Dynasty was not low, maybe tens of thousands of tons, which was not less than the Qing Dynasty after the Westernization Movement, but at that time, the whole country, countless blacksmiths gathered together, a city wall, even if it was a thin iron sheet, would have to be consumed, most of the iron, the effect was not good, three or four millimeters of iron, in the face of the attack of the landing siege machine, how much effect could it play.

Not to mention that the price of iron is very expensive, the market price of a pound of iron is about 80 Wen, a ton is 160 guan, 1,000 tons, if it is 10,000 tons, almost 1.6 million guan, not to mention the construction of other aspects of the city, which is unbearable for the Northern Song Dynasty, this proposal, almost at the beginning of the issue, was rejected.

Can iron be compared with cement, not to mention Zhao Xin, who knows the cost of this powder, even if Sun Ji and others who don't know, it seems that this powder has not added anything, and it should not be expensive, even if his price has reached the price of the previous foaming agent, as high as 1 pound, but its use is not as comprehensive and indiscriminate as steel, his use is dispersed, only used as a binder.

Yesterday, they all watched the entire synthesis process, and when the final product was brought back, it was also under their noses, and even now, the entire ratio quantity, Xue Yu and them, still remember it clearly.

The use is 1 kg of powder, 1 kg of lime, and 6 kg of sand, and then it is the stirring of adding water, and the subsequent process is not much different from the use of yellow mud paddle.

It can be said unceremoniously that in the whole binder, in addition to this powder, the others are the cheapest, lime may cost ten cents, which is relatively cheap, not far from Baozhou, after a mountain full of limestone, the work of mining minerals has already begun, and the daily lime production is quite huge.

To a certain extent, lime is still a commodity, and as for sand, even if it is Xue Yu and Sun Ji, it cannot be regarded as a commodity.

It is the rubble in the riverbed, it is not inconspicuous at all, if it weren't for Zhao Xin using this powder and using him, even if it is thrown in vain, no one will realize his effect, it will be used as a filling in the riverbed, flowing there in vain, and no clothes moth people will focus on their whereabouts.

Maybe in the future, sand will become a valuable thing like lime, but now, he really has no value, it is just something on the riverbed, as long as you give money, anyone can dig it, and in a short time, you can dig a lot.

A binder, seven-eighths of the things, all of them are cheap, worthless things for a household, even if this powder is added, it is quite expensive, and it will be as low as steamed bread to a certain extent.

Foaming agent is not expensive, the price of a pound has always been very expensive, it seems, expensive incomparably, among the bulk commodities, few commodities can reach such a price, but the use of each steamed bread is very small, on average, the foaming agent increases the price of steamed bread, but the taste and taste are greatly improved, in order to make money, no one will object to this price.

The price alone may be very high, divided by eight times, so that the price is reduced, such a price is acceptable, the most important thing is that the use of small amount, just the adhesive, and the whole iron wrapped before is quite different, even if the price is consistent in a catty, it is almost acceptable, because not all over the city wall, will use this powder.

The full set of equipment of the Northern Song Dynasty Forbidden Army, purely in terms of iron itself, will not be so expensive, but it adds a lot of labor and profits, but in the end, such a high price has become the first choice for the military to order because of its good protection ability.

If it is purely civil, not to mention the same price as the foaming agent, even if it is only one-tenth, or even one percent, it is more expensive, and no one will be willing to use it.

But it has a relationship with the military, and it can be used as a military aspect, in this case, the value of this thing has greatly increased, and in the military aspect, many things can be ignored, not to mention that it is not a so-called thing with a price higher than gold at all, but just a slightly more expensive thing.

Several people looked at this piece of rubble strangely, if it wasn't for the completion of the development of this thing, it would take more than 2 days to be able to combine the masonry into stone, which is a military benefit, it goes without saying, it's as simple as that.

It's not that they saw it with their own eyes, they couldn't even believe that a bunch of powder, some green bricks, actually had such a terrible effect, but the facts were in front of them, Xue Yu arrived later, he didn't see it, Sun Ji used one hundred and thirteen hammers to smash these things into powder, but everything in front of him proved this.

The three of them couldn't say a word, and finally Xue Yu broke the peace between everyone and said silently: "Why is this happening, it's unreasonable?" ”

Qu Yang pulled him a little worriedly, glanced at Zhao Xin's side, and said softly: "What's unreasonable, you think too much, there are four young masters, and even more unreasonable ones have appeared!" ”

Xue Yu's eyes lit up, yes, how could he forget Zhao Xin, the scene of meeting immortals, even the tiger car and the iron box car can successfully come out, what are the materials on a building, but deep in his heart, he can't help but be excited, yes, it's excited, city defense, this is a natural choice for city defense, with this, I am no longer afraid that it will collapse if I build too high.

Compared with Sun Ji and Qu Yang, Xue Yu's military career was a little bumpy, he participated in two of the three battles of the founding of the Western Xia Dynasty, both of which were defeats, and almost died and returned, among them, I have to say, the battle of Jinmingzhai.

Jinming Village is the frontier fortress of Yanzhou, which can be said to be extremely important, and it has been carefully arranged, but he is a village, not a city, facing the attack of 100,000 troops in Western Xia, only a small number of people can escape, Xue Yu is one of them.

If, at that time, Jinmingzhai could have such a powder and build Jinmingzhai as solid as Yanzhou, then the subsequent Battle of Sanchuankou would not have lost so badly.

Although Sun Ji did not participate in the Battle of Sanchuankou, he also fought in the northwest for many years, and the current situation of the northwest city defense was almost in his heart.

In his opinion, if, in the battle of Sanchuankou 5 years ago, Jinmingzhai could have this powder as a defense, and the city defense was a little stronger, relying on the defenders of Jinmingzhai, it could resist the attack of Western Xia, and there would be no defeat of Sanchuankou.

Zhao Xin's hearing is super long, and he can almost hear what the three people say, among the three of them, the focus of what he said is actually the adhesion of the cement, especially Xue Yu mentioned the height of the city defense countless times, if there is this powder, the city defense can be increased by one or two times the height, this kind of mention made his eyes shine.