Guo Dalu swaggered into the blacksmith shop: "Li Dayan, Blacksmith Li, are you drooling over the few broken knives I gave you?" I said it a long time ago, it's useless for you to force me, I only have these knives in my hand, as for how this knife was made, I can't understand it for a while, this involves a variety of trace elements, I only know that nickel, chromium, etc. need to be added to it, as for what nickel and chromium look like and how to get it, I don't know." ”

Li Dayan hurriedly put away the knife and glared at Guo Dalu dissatisfied: "I know that your knife must have been obtained from your life-saving benefactor, the old man in the mountain, you have followed him for more than ten years, but you have not learned the real skills, if I were your father, I would have slapped it a long time ago." ”

Guo Dalu shrugged his shoulders--The unknown old man in the mountain had become the best excuse for all his actions, and he had not been able to explain--Guo Dalu asked, "Uncle Li Dayan, how are the two small iron tools I asked you to make?"

Li Dayan stepped aside, took out two objects from the cabinet and handed them to Guo Dalu: "Just these two small objects, your Uncle Dayan will do it casually - I said, what are you going to toss about?"

Guo Dalu carefully looked at the two iron tools in his hand, one was an iron pen with a pointed tip, and the other was an iron plate, but the bottom of the iron plate was uneven and had countless fine particles.

Guo Dalu touched the fine particles on the iron plate and said with a smile: "Uncle Big Eyes is very good, these two objects can be of great use, I want to use them to print words on straw paper." ”

Li Dayan was stunned on the spot: "What? Printed words? This iron pen can be engraved on bamboo slips, but what is the use of this iron plate? I have only seen it printed with hardwood engraving, but I have never heard of it printed with iron plates bluntly." ”

Guo Dalu said with a smile: "How to use these two iron tools, you will know later, Uncle Big Eye, please invite Carpenter Zhou, let's discuss the matter of printing 10,000 pieces of fat Tianfang - I agreed to this matter, a manly man, a mouthful of spit and a nail, and I will do it." ”

Soon, Li Dayan, Zhou Carpenter, Hao Ge'er, and Silly Big Man came to Guo Dalu's house together, Guo Dalu faced everyone's curious eyes, and took out an object from his arms: "Put this thing on the iron plate, and then use an iron pen to engrave words on this thing, and then use ink to paint on this thing, you can print it on straw paper." ”

What Guo Dalu took out was a roll of wax paper.

Wax paper, iron pens, iron plates and ink, which in the previous school, but the most commonly used printing supplies, Guo Dalu used to see teachers in the orphanage to use these things to print newspapers and test papers, but later with printers, copiers, these handmade supplies were naturally eliminated.

Guo Dalu found a roll of wax paper in the garbage from the trash can, according to his guess, this wax paper should be discarded by a certain teaching office of the Normal College, and old items like this were thrown in the corner for a long time, just when they happened to clean up or something, they were sorted out, but in today's years when WeChat is flying all over the sky, who will use wax paper, naturally it goes directly into the garbage basket.

Guo Dalu had this wax paper in his hand, so he had the confidence to agree to print 10,000 pieces of fat fields in the yellow pen paste style to make a name for him, otherwise, if he really wanted to copy it, his hands would be broken.

Carpenter Zhou carefully took the wax paper in Guo Dalu's hand, spread it out in the sun, looked at it carefully, scraped it with his fingers, and even sniffed it with his nose, and hesitated: "What is this? But this paper is so thin, well, there seems to be a layer of wax on it." ”

Guo Dalu smiled: "That's right, this thing is called wax paper." Use an iron pen to engrave words on wax paper, and then paint them with ink, and the ink will be printed on the straw paper below from the place where the words have been engraved. ”

Li Dayan slapped his thigh heavily beside him: "Alas, this is a good thing, this is much more convenient than any engraving!"

Carpenter Zhou thought more: "Ink - Brother Guo said just now that he wanted to use ink, isn't ordinary ink good?"

Guo Dalu knows that although printing was invented in ancient China, oil-based ink has not been used for a long time, and movable type printing, especially metal movable type printing, is the most important thing is the use of ink, and wax paper needs ink more, and ordinary ink cannot be used at all.

Guo Dalu nodded: "Uncle Zhou is really smart, that's right, this wax paper must be printed with ink, but this ink is not magical, it's just that ordinary ink and castor oil are mixed together, as for what proportion of ink is most suitable for printing, you can try a few more times." ”

The stupid big guy next to him asked, "Proportion? What is proportion, is it delicious?"

Brother Hao patted him: "The proportion should be the weight, which refers to the difference between the amount of oil and ink - Brother Guo, let me do this, I will call all the children in the village, everyone will work together, and the best proportion of ink will be dispensed." ”

Guo Dalu smiled: "Okay, this is a trouble for you." By the way, when you do this with your children, keep a record of the different proportions of each ink. Well, let me think about it, I don't have a complete set of measuring cups here, and I don't have a standard measuring tool, so I have to trouble Brother Hao to find some bowls, and then find the bowl with the same amount of water in it, and make this measuring tool - Brother Hao, don't stick out your tongue, you will know the importance of standardized measuring tools in the future. ”

On this day, the villagers of Houlong Village found that when their children came home for dinner, they were all black-faced and black-handed, and when they inquired, they learned that Hao Ge'er took them to the mountains to cut pine branches, roast pine wood, collect charcoal ash, and collect castor beans, squeeze oil, and mix ink all over the mountain.

The adults originally wanted to scold a few times, but when they heard that they were following Brother Hao to help Guo Dalu do things, they repeatedly asked the children not to go to the field tomorrow, and to do Guo Dalu's things first.

At Brother Hao'er's house, the big girl saw that Brother Hao didn't even wash his hands, and while grabbing the nest head to eat, he stared at a piece of bamboo, muttering something "10 percent, 15 percent, the proportion of oil is a little less, increase the ingredients-", and said strangely: "What's the matter? What kind of devil is it? It's dirty like this, what is it like that?"

Brother Hao didn't raise his head: "It's proportion, not comparison, alas, you don't understand." Brother Guo said, the measuring tools in my hand are still too rough, and when he makes test tubes and balances in the future, he will be more accurate. This ratio is indeed troublesome, stupid big boy, this afternoon is a relatively easy ink, but this kid did not make accurate records at all, so there is no way to rematch it, which means that this work is all in vain. No wonder Brother Guo has been telling me about the importance of measurement and standards, so it is. ”

Erniu blinked beside her: "Measurement? I know, there are several buckets made of iron at the entrance of the Yinxian Yamen, as well as a few poles and tablets, I heard that it was left by Emperor Taizu's grandfather, and the world's shengdou scales must be based on this, if it is not allowed, but the head will be cut off." ”

Brother Hao snorted: "Those few shengdou are all fake! Who doesn't know that the grain collected by the yamen is all big buckets in and out of small buckets, and one out and one in the pit, I don't know how much grain we have worked hard to grow!"

Brother Hao's father Li Ruhai coughed heavily: "What do children know, talk nonsense, eat!" In fact, he knew in his heart that what Brother Hao said was true, the rules made by Emperor Taizu's grandfather had already collapsed after more than a thousand years, and he didn't know when the iron bucket at the entrance of the yamen had been quietly replaced by black-hearted officials. But there is nowhere to say anything about this matter, and it is reasonable? The official word has two mouths, and black and white are reversed. The thin arms of the common people can't resist the big thick legs of the government, as long as they don't die of hunger, these days are like this.

Brother Hao'er's face and hands were full of ink, but his eyes were dark and shining: "Brother Guo said that in the future, he will teach me physics, and physics is the truth of the world, as long as we learn physics, no one can pit us." He also told me and the stupid big guy a story about how to tell the truth about fake gold. ”

Li Ruhai was about to scold Brother Hao for closing his mouth to eat, when he heard that he was serious about fake gold, he was not only stunned: "Distinguish between serious gold? Guo Dalu has gold in his hand?"

Brother Hao shook his head: "Brother Guo doesn't have gold in his hands, but Brother Guo said that the real and the fake can be distinguished by the different qualities of different things." ”

Li Ruhai was confused: "Quality-what's quality? It's weight, right? Who doesn't know that gold is heavier than iron?

Brother Hao put down the nest in his hand: "Dad, it's the quality of the hostage, it's not the same thing as weight! Brother Guo told us that in a small country in the extreme west, there was a smart man with a big beard, and he was commissioned by the king to find out if the newly made gold crown was mixed with lead or something. ”

Listening to Brother Hao'er's story, Li Ruhai's family turned their ears sideways, and the eldest girl muttered: "It's not simple, put the golden crown on fire, this real gold is not afraid of fire, and the lead mixed in it will burn out as soon as it is burned." ”

Brother Hao snorted: "The king can say that he can't destroy the golden crown." ”

Don't talk about the big girl, Li Ruhai and Chen were also stunned, if this doesn't destroy the golden crown, how can they find out the truth and falsehood?

Sanniu whispered: "I know, this lead is lighter than gold, as long as you put the gold crown on the table and measure it, if the weight is light, it is a gold crown mixed with lead." ”

Li Ruhai shook his head: "Silly girl, this gold is a fraud method of containing lead, but it is the most commonly used in the rivers and lakes, as long as there is more lead in the gold, the weight of the light table is useless, only by twisting it with scissors and revealing the lead core inside, can you know whether it is true or false." The king of the small country in the far west gave the gold to the craftsman to make a golden crown, and the craftsman really had the intention to fake it, and mixed some lead into it, and he couldn't see it at all. ”