The world of film and television starts from the flow of money

The first quarter of the si hour.

The bluestone steps in front of the school were soaked with morning dew and shone with fine golden light under the rising sun.

The scale engraved on the side of the stone steps is clear, and every inch is carefully outlined with cinnabar. On the lowest step is a bronze ruler with small characters cast on it: "Produced by the Ministry of Works in the third year of Zhaowu". This is a standard instrument used to check students' steps.

The walls of the room were nailed with fine pinewood panels, which gave off a faint pine scent. Three huge pictures were hung on the boards: in the middle was the "Nine Chapters on the New Art", on the left was the "Pythagorean Calculation", and on the right was the "Grain Transport Mileage Calculation Table". Among the densely packed annotations on the pictures, some of the ink marks were still fresh, and it was obvious that they were added recently.

The most eye-catching thing is the line of tiny regular script below the "Nine Chapters on a New Art" with vigorous brushstrokes, which was written by the emperor Yi Huawei of the time.

Doctor of Mathematics Zheng Huaian stood in front of a rosewood lecture table, on which was a brass well logging instrument. He was about forty years old, with a short beard on his thin face, and an indelible ink stain on the second joint of his right index finger, a mark left by twenty years of correcting math problems. He was wearing an indigo official uniform today, with an ivory counting card hanging around his waist, which was given to him by the emperor himself for his meritorious service in surveying the land of the whole country at the Ministry of Revenue.

"Today's actual test."

Zheng Huaian knocked on the copper bell on the table. The sound was crisp and short, echoing in the room.

The students immediately quieted down, and forty pairs of eyes looked at him.

He raised the well logging instrument, and the copper ring shone coldly in the sunlight coming through the window lattice. "Target: the well in the courtyard. There is no limit to the method. Those who make an error of no more than an inch will be rewarded with a new type of counting sticks."

The room suddenly became abuzz. Zhang Dunshi, a short and fat student sitting in the front row, immediately opened the abacus bag embroidered with the Tai Chi pattern and took out a ruler and a square. Li Wenxiu, a handsome young man in the back row, took out a bronze sundial from his bosom and carefully wiped the dial with a silk handkerchief. In the corner, Zhao Tiezhu, a farmer's son, silently broke off a willow branch, squatted on the ground and began to draw.

Zheng Huaian's eyes swept through the crowd and stopped for a moment on Zhao Tiezhu. This farmer from Hejian Prefecture, who had only been a monk for half a year, could always solve the most difficult math problems with the simplest tools. He remembered that when he checked the homework last month, he found that Zhao Tiezhu's math book was made of waste paper used to wrap medicinal herbs, and it was densely covered with traces of calculations.

"I'll come first!"

Zhang Dunshi squeezed to the side of the well and tied the rope to a stone. The flesh on his round face trembled with his movements, and beads of sweat oozed from the tip of his nose. As the rope dropped, he squinted his left eye and stared at the knot with his right eye, muttering to himself: "Twenty-one feet... and seven feet..."

Suddenly, he shouted, "No! The water in the well is surging!" The rope was spinning on the water, disrupting the count.

Zheng Huaian calmly handed over a piece of sandalwood board: "Put it under the rope."

There are wave patterns carved on the wooden board. This is a special tool made by the Ministry of Industry and Water Resources, which is specifically used to offset the fluctuations on the water surface.

Zhang Dunshi wiped his sweat and started measuring again. This time he was extra careful and checked three times every time he put down a section of rope.

Zheng Huaian nodded secretly. Although this student was impatient, he was quite down-to-earth. He remembered that Zhang Dunshi's father was the head of the Ministry of Revenue and sent his son to study mathematics in the hope that he could take over his position in the Ministry of Revenue in the future.

In the corner, Li Wenxiu was using a sundial to measure the shadow of the wellhead. His white fingers moved on the sundial, and his brows suddenly frowned: "It's cloudy today..." He looked up at the sun that appeared and disappeared, took out a copy of the Zhaowu Calendar from his pocket, and quickly flipped through it to find the correction parameters.

"Use the 'heavy difference technique'!"

A hoarse voice came from behind. The tall and thin Zhao Tiezhu squatted on the ground and drew a diagram on the mud with a branch: "The diameter of the well is five feet, and the shadow is long..."

His rough fingers left deep marks on the mud, and there were several fresh wounds on his knuckles, which must have been caused by accidental scratches while working in the pharmacy yesterday.

Zheng Huaian knew that this farm boy had to do odd jobs for three hours every day at Renhe Hall in the east of the city after school in order to earn enough living expenses in the capital.

Suddenly, a fierce argument was heard in the room.

"The value of pi should be 'three diameters and one'! It has been like this since ancient times!"

The young man in brocade clothes, Liu Zongmin, slapped the Nine Chapters on the Mathematical Art on the table, his voice was sharp. He was the nephew of the Minister of Works, and he was always arrogant: "Zu Chongzhi's 'precision' is too complicated! Who has the patience to calculate so many digits to build embankments and canals?"

"absurd!"

The scholar Chen Weisong, who was standing opposite him, held up a newly printed copy of "Mathematical Essentials" and blushed in retort: ​​"Your Majesty clearly stated in "Essentials of Agricultural Administration" that embankments must be built using '22/7'! The Yellow River burst its banks last year because the embankment calculations were inaccurate!"

Zheng Huaian walked over slowly and took out a copper ring from his sleeve. This was a standard measuring tool specially made by the Imperial Observatory during the previous emperor's time. There were 360 ​​degrees of scale engraved on the ring. He rolled the ring on the table for two people, and the scale on the ring was clearly visible:
"We'll know after we test it."

Liu Zongmin's face turned red and white, and he wanted to argue, but was stopped by Zheng Huaian's eyes.

Zheng Huaian remembered that when he first entered the Imperial Observatory ten years ago, he was punished by the then chief supervisor to kneel for two hours because he insisted on using the "precision rate" to calculate the time of the solar eclipse. It was not until Yi Huawei ascended the throne and promoted the new mathematics that he was able to realize his ambitions.

Next to the courtyard well, Zhang Dunshi suddenly shouted, "I've got the number! Twenty-one feet and three feet!"

He waved the record book excitedly, and the fat on his face shook.

Zheng Huaian took the record book and glanced at it: "It's two inches off." He pointed to the joints of the blue bricks on the well platform and said, "The thickness of the mortar between the bricks was not taken into account."

Zhang Dunshi suddenly became depressed and slapped his forehead in annoyance. Zheng Huaian patted his shoulder:

"Remember, the way to measure is to see the big picture from the small details. Every brick and tile has a fixed number."

It’s almost noon and the sun is getting hotter.

Li Wenxiu's sundial finally came up with the result - 212 feet 8 inches. He carefully submitted the record, his hands shaking a little.

Zheng Huaian carefully checked his calculation process and nodded slightly: "One inch off, still okay."

This result is quite accurate considering the influence of today's clouds.

The last thing to be checked was Zhao Tiezhu's calculations on the mud floor. This farmer used the simplest branches to draw all kinds of figures and formulas on the mud floor. Zheng Huaian squatted down and carefully checked every calculation. To his surprise, Zhao Tiezhu not only used the "re-difference method", but also derived the correction formula himself, and finally came up with 21 feet 3 feet 1 inch - only half a centimeter away from the standard answer in Zheng Huaian's sleeve.

"reward."

Zheng Huaian walked back to the lecture table and took out a red sandalwood box from under the table. When the box was opened, the students around him gasped.

On the red silk lining, there were neatly arranged sets of ebony counting sticks, each with precise scales inlaid with silver wire, shining brightly in the sun. This was specially made for outstanding students by the Ministry of Internal Affairs after the emperor inspected the Mathematical Academy.

When Zhao Tiezhu took the counting stick, his dark hands trembled slightly. He suddenly knelt down and kowtowed heavily towards the direction of the imperial city: "I will use this counting stick to measure all the rivers and mountains in the world for your majesty!"

His voice was choked with sobs, and he rested his forehead on the bluestone slab for a long time.

Zheng Huaian's eyes were slightly hot as he recalled the time when his teacher gave him a set of bamboo abacus sticks when he was still a poor student 20 years ago. He still treasures the abacus sticks in the deepest part of his study, although they have long been worn out and the scales can no longer be seen clearly.

Back in the studio, Zheng Huaian caught a glimpse of the newly added line of imperial annotations at the bottom of the "Nine Chapters on New Techniques" which stood out in the sunlight:

"The key to mathematics lies in measuring fields, measuring stars, and understanding people's hearts."

He gently stroked the handwriting, and recalled the scene when the emperor visited the Mathematical Academy in disguise. That day, Yi Huawei wore the clothes of an ordinary Confucian scholar and stood in the last row to listen to the whole class. After class, he walked to the lecture desk, pointed to a problem in "Nine Chapters on the Mathematical Art", and discussed the solution with Zheng Huaian for half an hour. Before leaving, the emperor revealed his identity and wrote this line of words on the picture with his own hand.

"Doctor, there is something I don't understand."

Zhao Tiezhu stood behind him without knowing when, holding the precious abacus in his hand: "Why does His Majesty attach so much importance to mathematics?"

Zheng Huaian looked at the well outside the window, the nine knots on the windlass swaying gently in the wind: "Ten years ago, the Yellow River burst its dike and flooded three prefectures and eighteen counties. It was not because the dike was not strong, but because of miscalculation, the dangerous section was underestimated by three meters. Five years ago, when we conquered the Western Regions, the army got lost in the desert and lost more than half of its troops because the guide did not know how to calculate the position of the stars." He turned to look at Zhao Tiezhu, his voice low: "The emperor said that mathematics is not only about numbers, but also about the safety of the country. A slight mistake can lead to a great error."

Zhao Tiezhu nodded thoughtfully and carefully wrapped the counting sticks in a piece of washed bleached coarse cloth. Zheng Huaian noticed that there were still some medicine stains on the cloth, which must have been the packaging cloth he picked up from the medicine store.

"Tiezhu, starting tomorrow, you stay after school and I will teach you the advanced algorithms in the Ji Gu Suan Jing."

Zheng Huaian suddenly said: "You are very talented in measurement, don't waste it."

Zhao Tiezhu raised his head suddenly, with disbelief in his eyes, and was about to kneel down again.

Zheng Huaian held him up and said, "In the Mathematics Academy, we only care about knowledge, not status."

This is what he often said to his students, and it is also the core of Yi Huawei's new policy - promotion based on merit.

Outside the window, Zhang Dunshi was still measuring repeatedly by the well, vowing to find out the two-inch error; Li Wenxiu was sitting in the corridor, carefully recording today's calculation process; even Liu Zongmin put away his arrogance and studied the scale on the copper ring with Chen Weisong.

Zheng Huaian stroked his beard, with a gratified smile on his face. He knew that some of these students would go to the Ministry of Revenue to calculate land taxes, some would go to the Ministry of Works to build dams and bridges, and some would go to the Imperial Astronomical Observatory to observe the stars and calendar. But no matter where they go, the abacus in their hands will measure a more accurate future for this dynasty.

He looked at the imperial inscription again and suddenly understood the emperor's deep meaning. Mathematics measures not only the universe, but also people's hearts and minds, and the rise and fall of a country.

Only a dynasty that can accurately calculate the size of rivers and mountains can achieve eternal peace.

...............

The nine experimental fields in the backyard of Nongzhengzhai were shining brightly in the midday sun.

Each ridge is 30 feet long and 5 feet wide, with a half-foot high ridge built with blue bricks around it. Numbers are written in white lime on the ridges: "A-shaped ridge - brown soil in northern Zhili", "B-shaped ridge - red soil in southern Zhili" to "R-shaped ridge - tidal soil in Huguang".

There is a one-foot-wide walkway between the furrows, covered with a layer of fine coal slag, which makes a rustling sound when stepped on.

Li Laoshi, the agricultural policy instructor, squatted beside the "C-shaped field". He was about fifty years old, and the wrinkles on his face were as crisscrossed as the ridges of a field. The front of his coarse cloth shorts was stained with mud, and he had a copper shovel on his waist, the handle of which was polished to a shine. His palms were rough like tree bark, and there was mud stuck between his fingers.

"Okay."

Li Laoshi bent down and grabbed a handful of soil. He clenched his five fingers and the soil broke into fine powder in his palm. He spread his palm and brown soil particles fell from his fingers: "The soil in northern Zhili will disperse quickly if you squeeze it tightly. It lacks stickiness. Why?"

He blew a breath, and the dust flew up. "This is sandy soil, it can't hold water."

Twenty students stood in a circle. The tall and thin man in the front row quickly wrote in his notebook: "Sandy soil, need to apply more green manure."

Several students from Jiangnan in the back row frowned, because the soil in their hometown could be crunched into a ball.

"Next is sniffing."

Li Laoshi took a handful of soil from the No. 4 field and took a deep breath of it in front of his flat nose: "The soil in Nanzhili has a fishy smell, like freshly caught river fish."

He turned around and handed the soil to the student next to him: "Smell it."

A young man in brocade clothes took it hesitantly, and just after sniffing it, he leaned back sharply: "This... this is clearly a foul smell!"

"It's stinky."

Li Laoshi grinned, revealing a missing front tooth: "Your Majesty wrote in the Edict to Encourage Farmers: 'The stench of manure is actually the fragrance of rice and millet.'"

As he spoke, he suddenly pulled out a booklet from his bosom, with a red seal on the cover: "This is the 'Secrets of Identifying Soils' bestowed by the Emperor, pass it around and have a look."

When the booklet was passed to the third student, Li Laoshi had already squatted in front of the fifth field. The soil in this field was red and was specially transported from Huguang. He picked up a piece of soil and stuffed it directly into his mouth in front of everyone's astonished eyes.

"acid."

He smacked the taste, his sparse white eyebrows knitted together: "It's three points more sour than last year."

After spitting out the residue, he untied a leather bag from his waist and poured out a handful of grayish-white powder: "According to Article 32 of the Zhaowu Agricultural Policy, it should be mixed with lime."

A brave northern student tried to imitate him by tasting the soil, and immediately spit it out.

Li Laoshi was not annoyed, but laughed and clapped his legs: "Great! Do you know how powerful it is? His Majesty said that if an agricultural official dares not even taste the soil, he should go home and hug his children as soon as possible!"

He suddenly stood up and led everyone to the newly built "Soil Inspection Pavilion" beside the field. On the stone table in the pavilion were nine sets of instruments: copper scales, pottery bowls, fine sieves, water buckets... Each one was polished to a shine.

The most eye-catching thing is a brass "acid-base tester", which is said to have been made by the Ministry of Works according to the drawings drawn by Your Majesty himself.

"Now we will divide into groups to test the soil."

Li Laoshi knocked on the iron plate hanging on the pavilion pillar. On the plate was engraved the "Regulations of Agricultural Administration": "When measuring soil quality, three tests must be remembered: the first is the feel by hand, the second is the instrument test, and the third is the seedling test."

The students started to work in a panic. The group of young men in brocade clothes sifted the soil sample too finely, so Mr. Li hit the back of his hand with his pipe:

"Fool! His Majesty said that the soil should be left three-tenths rough!"

The other group had too much water in their buckets, so the old man just picked up the bucket and threw away most of it: "Remember Article 59 of the Regulations on Encouraging Agriculture - the combination of water and soil is like mixing soup!"

As the sun rose higher, a bell rang in the room. Li Laoshi took out an oil-paper bag from his arms, which contained a pancake mixed with bran. He broke off half a piece and gave it to the student who dared to taste the soil: "Eat it, this is what your majesty ate when he inspected the river works."

Suddenly, there was a commotion at the gate. An officer hurried over with a wooden box in his hand: "Teacher Li, the palace has just sent some sweet potato seeds!"

Nine purple-red potato seeds were neatly arranged on a red silk background in the box. Each one had a label indicating its origin. The most special one had a golden skin and the label read in red ink: "New seed from Southeast Asia, yield of 15 dan per mu, personally tested by Your Majesty".

Li Laoshi took it with both hands, turned around and said to the students: "See? This is what your majesty said in the "Edict to Encourage Agriculture" that 'agriculture is the foundation of the country'."

His rough fingers stroked the potato seeds, a smile appeared on his face, and his wrinkles seemed to deepen: "At this time last year, the potato seeds sent by the palace were ordinary..."

The students gathered around, and someone found a note at the bottom of the box. Li Laoshi unfolded it and read, "'The soil tested by the students will be reported to the cabinet in three days' - the signature is the private seal of His Majesty!"

Everyone suddenly became solemn.

The student who tasted the soil suddenly knelt down and kowtowed three times towards the direction of the imperial city.

"Long live my emperor! Long live!"

The rest of the students followed suit, and a muffled sound was heard on the blue brick ground.

(End of this chapter)