Two hundred catties of material is not much, and clay is not far from the sea; There is no shortage of lime stones. And in addition to charcoal, Zhou Nan knew that the people of this era, not to mention in the Great Song Dynasty, were in the Yanjing area, where wealthy families and craftsmen who made iron and burned porcelain already used coal as fuel, but people in this era were used to calling coal coal.

  This is what Ding Yuanmu told him. Ding Yuanmu can be regarded as a prisoner in the Great Liao Dynasty for half his life, but it is a pity that his family is not very prominent, and he only relied on his own imperial examination to become an official, and he only became an inconspicuous general and a young eunuch.

  Although Zhou Nan said that he wanted to recruit skilled craftsmen from all over the country and enrich the generals as supervisors, and also adjusted the functions and composition of the generals, Zhou Nan did not really understand the Great Liao generals as prisoners, and he didn't even know what kinds of skills there were in the prisons.

  Thanks to Ding Yuanmu, when Ding Yuanmu was in Zhou Nan's spare time, he carefully explained to Zhou Nan the details of the Great Liao General's prison. The officials in charge of the Da Liao will be the chief eunuchs, and the officials of the three products will be in charge of the four departments and the three supervisors and hundreds of workers. There are also young eunuchs below the chief eunuch to assist the chief eunuch in managing the affairs of the prison. The prison is divided into Nakasaku (for weapon making), Iron for iron smelting, Silver for silver smelting and silver casting, Cheziyuan for the manufacture of vehicles and ships, Fenzhuyuan for the construction of Miyagi, Stone Sculpture for stone carving, Koji and sake brewery for sake brewing, as well as the Salt Temple, Printing and Dyeing Temple, and Ayajin Temple.

  As for why there are no professions such as leather courtyards, ceramic courtyards, and printing courtyards in the prison, Ding Yuanmu explained that some are because every Khitan family can do them, and there is no need to set them up, like leather courtyards; In some trades, there are too few craftsmen, and there are also substitutes from the Southern Dynasties, such as ceramics and printing.

  In Zhou Nan's view, these trades are far from enough, such as papermaking, sugar making, processing of various fine objects, casting, etc., as for the subdivision of these trades, it is the matter of craftsmen. At the very least, it must be complete, and you can't rely on the Great Song Dynasty. On the basis of complete development, it will be improved and gradually catch up with the technological level of the Great Song Dynasty.

  If the cement is trial-produced this time, it can be regarded as an aspect of improving its technical level, at least not in the Great Song Dynasty.

  A few days later, Zhou Nan asked six craftsmen to prepare the fine powder of lime and clay sintered and grinded, and only gypsum was collected in the nearby state and county crude medicine shop 60 or 70 catties. But it's enough.

  In the area of Zhounan's hometown, guarding the foot of Taihang Mountain, there are many small cement factories of all sizes, and there are even workshops that are not even factories. The eight immortals crossed the sea to show their magical powers, all went to produce cement, and they all had ways to sell it. Zhou Nan has classmates who do this at home, and they know some of the things inside, especially for the production equipment and processes are simple soil cement.

  Zhou Nan first inspected the fineness of the clay powder and lime powder ground by these craftsmen, and the higher the fineness of the cement, the higher the strength of the cement produced. Zhou Nan didn't have a sieve at hand, so he could only rely on the general feel. Fortunately, Zhou Nan only set a weight of 200 catties, and the powder ground after clay sintering was already very delicate. The remaining lime and gypsum are easier to grind, and Zhou Nan is relieved.

  Under the command of Zhou Nan, these craftsmen took 75 catties of clay, 22 catties of lime, and only 3 catties of gypsum, and then mixed them together and stirred them evenly.

  When these things are done, the cement is done. Zhou Nan asked two bricklayers to take 50 catties of cement, mixed with 100 catties of clean fine sand, mixed in water, stirred evenly, and formed into a slurry, and then let the two bricklayers first use cement slurry to build a round stool, and then used the remaining cement slurry to make several round cake-shaped specimens about one finger thick and the size of a palm, and made twenty or thirty square cement blocks the size of fingernails. Although there is no curing box, and there is no Lei's clamp, but make two test pieces, let the craftsman manually maintain for a day and a night, you can basically see the stability of the cement you make - you can't use cement for construction first, and then wait a month to see the performance of the cement, right? As for those small squares, Zhou Nan was going to use them to measure the strength of the cement.

  The craftsmen watched the gray mud slowly condense and were amazed. Zhou Nan told the six people: Find a house, make a fire in it, ask people to wear only single clothes in the room, put these objects into it, and boil a pot of water next to these objects to keep the heat going. Wait for a day and a night and come to him with these things.

  At the same time the next day, these craftsmen came to see Zhou Nan nervously holding these cement specimens. Although these objects were the same as yesterday, they did not know whether they were good or bad.

  Zhou Nan took the two round cakes, only to see that the round cakes were still intact, there was no crack, and there was no bulging place on the round cakes, although there was no ruler to detect, but only the naked eye could see that the surface of the round cakes was not curved. This shows that there is no problem with the stability of the cement produced by yourself.

  As for the strength of cement, Zhou Nan only knows a rough idea, the cement number produced by the soil method is generally two or three hundred, and the cement of one hundred can withstand a pressure of 100 kilograms per square centimeter.

  Sorrowful! What a sorrow for liberal arts students!

  According to the physical definition in his mind and his understanding of the cement label, Zhou Nan said to these craftsmen: "Take three 100-kilogram square stones, and then take two 50-kilogram stones." The remaining cement specimens continue to be cured in the house. ”

  There were stonemasons, and there were more stones, and several craftsmen soon brought the stones that Zhou Nan asked for. After the three-day curing period was up, Zhou Nan asked people to take the cement blocks and began to test the strength of the cement.

  Zhou Nan asked one of them to start recording, and he commanded the rest to test the more than 20 square cement blocks one by one to see how much pressure they could withstand.

  Through continuous testing, a total of 28 cement blocks can almost withstand the pressure of 100 catties, and even a few can reach 150 catties.

  This is only for three days, if you maintain for a month, the intensity will be higher, or even double. More than 200 grades of cement can already meet the requirements of building multi-storey buildings. Zhou Nan is quite satisfied with such a result.

  The six craftsmen and the young eunuch Ding Yuanmu were even more dumbfounded. Ordinary soil and lime and gypsum are mixed together, and they are stronger than bluestone, and the most amazing thing is that they can be molded at will.

  "Master Pony, with this cement, it will be easy to build Shanhaiguan City." Ding Yuanmu said in amazement.

  "Not only that, but the cement also binds the two stones together as one. You can give it a try, and when it's time to build the castle, you can use it as you wish. Zhou Nan saw that the cement trial production was successful, breathed a sigh of relief, and said to these craftsmen.