In the spring of the twelfth year of Zhenguan, 26 prefectures, including Shannan West Road, Huainan Province, and Jiannan Province, continued to drought, and the disaster was very serious. Therefore, at the beginning of May, the atmosphere in the court suddenly became tense.

Especially the emperor Li Shimin, who was even more troubled.

In the event of a large-scale drought, flood, or locust plague in these years, it is easy for the common people and civil and military officials to blame the emperor. After all, there is a saying that the sky has fallen and there is a high top, and now the highest 500 million in the Tang Dynasty is the emperor, and this hat is just right for him to wear on his head.

Therefore, at the end of April and the beginning of May, Li Shimin summoned his eleventh lang into the palace twice in a row, and asked Li Yuanjia, the king of Han, to ask about the progress after being called, and after asking about the progress, he could scold him fiercely and vent his unhappiness!

Li Yuanjia is also very annoying, but what can he do?

The weather is hot, and Li Yuanjia, who can't lose his temper at the emperor, and has nowhere to vent his bad mood, can only spill his anger on the one-third of an acre of land in his Han Wangfu - this kind of transfer of pressure is undoubtedly full of the atmosphere of the weak, but Li Yuanjia will only regret it every time he gets angry, and then quickly forget about it......

On the seventh day of the fifth month, the major stewards gathered again in the Han Palace.

After everyone arrived, Li Yuanjia waved his hand at Chunyan and said lazily: "One set of things for each person, let's send them all down." ”

"Yes, King!"

The two girls, Chunyan and Liu Mei, immediately started to do it, and sent down the things that had been prepared a long time ago. Including Ma Liang, who taught in the palace, everyone received four tools that had just been made.

"Got it...... Got it......"

Just when everyone was carefully looking at the things in their hands and pondering their usefulness, Li Yuanjia listened to the bursts of cicadas on the book, and his heart was irritable for a while.

Hot!

It's so hot!

Not only is there a continuous drought in more than 20 states, but Chang'an City in early May ...... If it is changed to the Gregorian calendar, it should be June and July...... It's also extraordinarily hot!

The night is better, after all, the craftsmen in the house have already made bamboo mats, and Li Yuanjia can take off his clothes when he sleeps, and put a lot of ice cubes next to the bed to greatly reduce the temperature in the room. Like many bigwigs in Chang'an City, when they sleep, there will be maids who take turns standing by the bed and fanning, and they will not suffer much crime.

But during the day, especially when you want to meet people, there's not much to do.

So Li Yuanjia didn't want to waste time, so he waited for more than ten seconds, and after letting several people see this set of tools clearly, he said directly: "It's all good, a ruler, a triangle, a compass, and a protractor...... Don't ask me why it's called that, just ask if this king likes it! Don't ask me how to use these things, if you want to learn, go to Chen Mu, these things are all made by him! ”

“……”

After listening to Li Yuanjia's words, everyone was silent.

can hear that the king is in a very bad mood.

But no one knows what he's bothered about, just as no one knows why the king would summon everyone here at this juncture.

After all, in ten days, it will be the day when King Han and the eldest daughter of the Duke of Liang will get married!

Now the entire palace is busy around that day, and most of them have put down the things at hand and obeyed the orders of the housekeeper Han Shan. And in order to make everything go smoothly, the Zongren Mansion even sent more than a dozen people to help with it, and it seemed that there were endless things to do every day......

The entire palace seems to be idle.

Li Yuanjia, who had already completed the wedding etiquette training with the old man sent by the Zongren Mansion, was staring at a few of them at this time, squinting and said: "I don't care what you are using now, or what you are used to using, in short, by the end of June, I will learn to use these tools and learn to use those new units-if Chen Mu can't teach it, he will follow Ma Liangxue, understand?" ”

"Understood, King!"

"Alright, let's all disperse!"

After scaring the housekeepers so much that they didn't dare to take a breath, Li Yuanjia only felt that his irritability suddenly dissipated a lot, and simply waved his hand to let the gang all disperse.

It's just some simple measuring tools, and I believe it is not difficult for them to learn to use them, but the difficulty should be to get used to the new units of measurement. After all, for them, they have been accustomed to measuring length with inches, rulers, zhangs, etc., and now it is indeed a bit difficult for them to get used to using millimeters, centimeters, minutes and large rulers all at once.

But there is no way, Li Yuanjia needs a decimal standard length system.

So he used the ruler given to him by Li Shimin as a benchmark, and forcibly "created a benchmark unit of length - the big ruler!"

Three feet is a big foot, which is about 90 centimeters or a little more?

Although Li Yuanjia also wanted to use the distance from the earth's equator to the north pole on the meridian of the emperor's throne in the Daxing Palace in Chang'an as a standard, it is a pity that Li Yuanjia not only did not know how to calculate this standard, he did not even know the principle......

In fact, Li Yuanjia felt that the name "big ruler" was so ugly that he once wanted to call it "meter" or "meter" directly, but after hesitating for several days, he really couldn't figure out how to explain the origin of these two names. After all, "meter" is transliterated, and "meter" means the ruler of the metric system, which is impossible for people in this era to understand.

So three feet is one big size, which is just right.

Rushing to the palace from outside the city under the sun, after listening to a few reprimands from the king, several supervisors went back in confusion. Looking at the blank faces on their faces when they left, Li Yuanjia took a deep breath and felt as if his mood was a lot more relaxed in an instant.

So lying on the recliner, Li Yuanjia moved his chin at Liu Mei in a happy mood: "Girl, bring me a glass of juice, try to be as cold as possible......"

……

"Dad, what's wrong with our king?"

After leaving the small courtyard where Li Yuanjia was, Han Lucheng asked cautiously: "Why did you suddenly let everyone start using new tools, and they were so eager?" ”

"Hehe, you ask me?"

"Ah...... Oh, yes! ”

"Hmph, you ask me, who do I ask?!"

Glaring at his son fiercely, Han Shan said angrily: "And you can actually guess the king's thoughts?" Just do it! ”

“…… Be! ”

Secretly rolling his eyes, Han Lucheng could only respond aggrievedly.

However, after walking all the way back to his small courtyard, after entering, Han Shan suddenly patted his son's shoulder and said in a low voice: "Give me some spirit these days, don't make mistakes!" I always feel that the closer to the wedding day, the bigger the temper of our king, but don't be stupid enough to touch the moldy head......"