The Great Qin Empire---Qin Li

"Supervisory Censor, go further and you will reach the last section of the wall." The black-clad clerk ran to the front of the carriage to report.

Supervisory Censor Linglu nodded, closed the bamboo slips on his knees, and asked: "Whose camp is this?"

"It is Lieutenant Li You, who leads the soldiers and civilians of Nanjun, and sent the military commander Zhang Han to supervise the construction."

"Li You and Zhang Han?"

Linglu pondered for a moment and thought to himself: "Li You is the son of Li Si, the court judge. At a young age, he became the left minister and was in charge of the military affairs of a county. The king has high hopes for him. Zhang Han is an official of the Shaofu, and is also known for his ability."

"I wonder if the corner towers of the wall built by these two people are any different?"

Turning his head in the carriage, Linglu could clearly see that on the horizon with withered grass and yellow trees, there was a wall more than ten feet high and stretching for hundreds of miles. It is like a yellow curtain, artificially dividing the Huaibei Plain, with Qin to the west and Chu to the east. Every hundred steps, there is a corner tower more than two feet high on the rampart, with drums and flags on it, and a group of fully armed soldiers holding crossbows standing guard vigilantly on it.

This is the fifth day since Linglu set out. He was originally a supervisory censor, subordinate to the censor's office, and was arranged in the county to supervise officials and report directly to the King of Qin. Together with the county lieutenant, he curbed the powerful county governor.

The supervisory censor also has the responsibility of supervising the administration of various departments in the county, and discovering talents in the local area and recommending them to the central government. In wartime, Linglu, as the "supervisory censor of Chen County", had to change his identity and serve as Wang Jian's envoy to supervise the progress of engineering and canal transportation on the front line.

The entire rampart is divided into thirty sections, basically each section is five to ten miles long. One mile in Qin is 300 steps, so three corner towers must be built for each mile.

Along the way, Linglu was not very satisfied with the quality of the entire project. Perhaps it was because of the soil quality. In his eyes, these hastily built ramparts and corner towers were really bad. Especially the corner towers, which needed stronger hardness than the ramparts. But Linglu asked people to chisel and peck with the spears in their hands, and a large piece of rammed earth on the corner tower would fall off. Some military commanders built corner towers with adobe, mixed with straw and branches to increase the bonding strength, which barely passed the test.

"But if the Chu army comes to attack, it is still not difficult to destroy this corner tower with flying stones!"

The so-called flying stones are catapults, which were made by Fan Li during the Wu-Yue hegemony. They have always been a common tool for sieges and defenses and fortification battles. They are generally ineffective against thick city walls, but they are the nemesis of corner towers and watchtowers.

Linglu could imagine that when the Chu army attacked in large numbers, they only needed to send a ten-jin flying stone to hit the fragile corner tower several times, and the fragile corner tower would collapse...

Therefore, he had very strict requirements on the quality of the corner tower, and punished several military Sikongs in succession, and asked them to bring civilians to reinforce the corner tower.

Along the way, the supervisor, who was quite familiar with civil engineering, had a gloomy face until he arrived at the southernmost section in charge of the Nanjun soldiers, and then he showed a trace of surprise.

The fortress in charge of the Nanjun civilians was no different from what he had seen before, but Linglu found the unusualness of the more than ten corner towers at the first sight from a distance...

Looking from a distance of hundreds of steps, the red-yellow corner towers were tall and thick. When he got closer, Linglu found that their bottoms were piled with large pebbles or blocks of stone.

"This is to prevent rain from soaking and making the corner tower unstable." Zhang Han, the military commander in charge of this section, hurried over to meet him and explained.

"If it is built with pebbles, it won't be pried open?"

A clerk beside Linglu asked, but Linglu glared at him: "Don't you see that these big pebbles are deliberately placed with the big end facing inward and the small end facing outward?"

Linglu is not an amateur who knows nothing. On the contrary, he has worked in the Shaofu for a period of time and even participated in the excavation of Zhengguo Canal.

He knows very well that it is extremely difficult to pry the big pebbles from the outside after the foot of the wall is pressed by the heavy rammed earth wall.

Sure enough, after several civilians pried with iron hoes for a long time, the pebble foundations did not move at all...

Even if the Chu army came close and wanted to quickly pry it out with a hole attack, it would not be easy for such a corner tower foundation.

Linglu was quite satisfied. He raised his head and touched the outer wall of the corner tower. It was hard and dry. This was what surprised him the most. The exterior of the corner tower looked like stone, and it was more resilient. When people hit it with iron tools, it made a sound of metal and stone! It takes a lot of strength to break the wall. Where can such good soil come from nearby?

"This is three-in-one soil."

Zhang Han explained his doubts and invited a black-faced leader to come over: "We also used ordinary loess to tamp it at first, but because of the poor soil quality, the corner tower we built was fragile. Fortunately, Leader Heifu taught me the way to build houses in his hometown..."

"Oh?"

This was new. Linglu became interested and asked Heifu and Zhang Han to explain it in detail.

"Use common loess, add fired mirage ash and river sand, mix them together, this is the three-in-one soil."

It sounds simple to Heifu, but the project in the past half month is not easy. First, the civilians have to pound the loess into fine powder and ferment it to become cooked soil, and then dig fine river sand from the nearby river and transport it across several miles.

This is not a big deal. The most troublesome thing is the firing of "mirage ash". Mirage ash is also called oyster ash. Oyster shells are fired to produce a product similar to lime. Qin used this material in building palaces and bridges, as well as building houses and repairing ditches. It is said that it is more prosperous on the coast of Yanqi.

Although common sense tells Heifu that firing limestone can definitely produce similar products, where can you find limestone deep in the front line? Anyway, there were only a dozen or so corner towers to be built, so the traditional method was used to burn some oyster shells from the Ru River and its tributaries. Because the quantity was limited, the ash only accounted for one-fifth of the proportion of the three-in-one soil.

After mixing the three together, they had to be constantly beaten and turned with a wooden hammer, and then piled and left for a period of time to allow it to blend and ferment. After a few days, it could be used as a building material.

The construction process was still rammed earth, but it was necessary to continuously sprinkle water and wet ash and rammed alternately to consolidate the three-in-one soil. At the same time, some gravel was added for reinforcement. After thousands of people worked for half a month, the solid corner tower in front of them was built, which had better performance than ordinary corner towers.

Linglu's eyes lit up as he listened, and finally he waved his hand and asked people to use the catapults in the army to hit a corner tower built with three-in-one soil!

The aim of the flying stone weapon was very low, but the first hit was too high, just brushing the edge of the corner tower. The second hit was also off-center, and it was not until the third hit that the stone weighing more than ten pounds hit the middle of the corner tower!

Corner towers are different from city walls, and flying stones are their nemesis. If it were an ordinary corner tower, a large piece would definitely collapse, but this corner tower built with three-in-one earth did not move at all. When everyone rushed to the side and took a look, they all gasped. It turned out that the stone only smashed off a palm-sized wall and left a small groove...

Hei Fu's heart was finally put down. Although the strength of this three-in-one earth corner tower was far inferior to the earth tower he saw in later generations due to the insufficient proportion of lime, it at least withstood the test.

His hometown in his previous life was in the south, and there was an ancient earth building in the town, which was built with three-in-one earth. I heard that in addition to loess, lime, and river sand, glutinous rice soup, egg white, shell powder, gum, brown sugar and other things are also added. To exaggerate a little, the earthen buildings made in this way are simply invulnerable to swords and guns!

In his previous life, Heifu heard from some old people that in the early years of war, some people tried to break the building with cannonballs, but the result was that the earthen building was only hit by a few small pits. In that special decade, someone tried to demolish an earthen building, but it was not opened by swords, guns, sticks and clubs. In the end, dozens of kilograms of explosives were used to blow it up, and a piece collapsed...

It can be seen that its strong resistance function can be said to be unprecedented in this era! With the strength and accuracy of the slingshot, it would probably take more than ten slingshots and half a day to destroy one.

However, every advantage has its disadvantages. The biggest problem with rammed earth is that it is too expensive. Even without glutinous rice soup, egg white and other things, it is still two or three times more expensive than an ordinary corner tower...

So, when Ling Luxiao asked them how much manpower and time they spent, Zhang Han and Hei Fu also cleverly apologized to Ling Lu: "I dare to tell you, the more than ten corner towers, the more manpower and manpower spent are more than ordinary corner towers..."

Ling Lu didn't care: "The corner tower is used to defend the enemy. What's the point of building a corner tower that collapses at the first blow?"

"General Wang ordered us to defend it with a strong wall. What is a strong wall?" He patted the corner tower made of rammed earth again with love: "This is called a strong wall!"

His face changed from the gloomy haze of the past few days. He praised Hei Fu and Zhang Han and said that he would ask General Wang for credit for them! Zhang Han also looked at Hei Fu, quite grateful.

"This building made of rammed earth is simply indestructible! If it can be promoted and used elsewhere..."

As a supervisory censor from Xianyang, Linglu knew that the King of Qin's goal was not only to destroy Chu, but also to rule the world. When the king was looking at the maps, he also showed great interest in those seemingly barren and barbaric places around Kyushu.

"Everywhere people go, there are all vassals!"

This sentence sounds so thrilling and exciting.

The role of the corner towers and fortresses built with rammed earth in this war to destroy Chu is actually very limited, but the future prospects are very promising!

Linglu thought far ahead, but at this moment, a fierce drumbeat broke his meditation!

"Dongdongdongdongdong!"

The drumbeats were urgent and sounded from the corner towers, deafening! The soldiers on top were still holding flags and shaking them desperately!

The civilians were a little flustered, but the Qin soldiers who were waiting for a long time wearing armor and spears were cheered up!

"Light the beacon!"

Under Hei Fu's order, the soldiers immediately lit the dry dung and firewood prepared on the corner tower. The thick smoke billowed and drifted obliquely to the blue sky of winter with the north wind...

Soon, countless black smoke rose from the south to the north of the Qin army's two-hundred-mile barrier, telling hundreds of thousands of Qin soldiers along the line a message:

"The Chu people are coming!"