Everyone on the embankment clenched their fists and breathed hard.

They all shouted loudly.

"Please rest assured, we will do our best!"

"I'd rather die of exhaustion on the river than be lazy."

"Three days, that's enough!"

The last sentence was said by Ye Lao, which made Wang Xianling's expression move, and he couldn't help but look at it with a little surprise.

When he went to find Ye Lao before, he still said such confident words.

However, Ye Lao didn't explain anything, only looked directly into Wang Xianling's eyes, and seemed to be confident.

Wang Xian Ling didn't ask any more questions, and immediately handed over all the calculations to Ye Lao.

And immediately the crowd dispersed, and every man made preparations.

The channel chosen to be dug is extremely narrow, and the sound of rushing water can be heard from a distance.

It can be seen that the water potential is turbulent and the difference is not small, which is very suitable for flood discharge.

When everyone looked closer, the slope of the river was indeed very large, and the rocks on the bank were angular, apparently impacted down from the upstream by the current.

It can be inferred that the soil in the upstream mountains must be loose, and the sparse mountains and forests will not be able to conserve water and soil.

But the upstream are all deep mountains and old forests, how can the trees be sparse?

Now is not the time to think about this, flood discharge is the most important thing.

Walking forward for a while, Ye Lao raised his hand to stop.

He instructed a few people to step forward and carefully measure the height of the embankments in many places.

He also arranged for people to tie ropes and ride a bamboo raft deep into the river, and touched the situation of several riverbeds.

However, these are relatively simple measurements, and the most complex ones are the long-distance measurements of gentle slopes and depressions.

With miles of gentle slopes and extremely irregular depressions, it is definitely quite difficult to measure each section accurately.

Everyone racked their brains and tried several times to no avail, and the measurement speed quickly slowed down.

It was only at this time that Ye Lao realized that the arithmetic secret techniques he had learned before were actually a little insufficient!

Looking at everyone's sad looks, Chen Ping did not rush to show off.

Instead, he walked up to Ye Lao and whispered a simplified version of the method of light and shadow measurement.

The method of light and shadow measurement.

In fact, it is not completely absent in this world, but it is still in a very early stage, and the restrictions are not small.

For example, on a sunny day, erect a fixed-length bamboo pole, and then use the ratio of the length of the bamboo pole to the shadow of the mountain to calculate the height of the mountain.

But there was no sun at this time, and the rain made everyone's vision blurred, and even the shadows were gray and weak.

The light and shadow measurement method provided by Chen Ping can be used smoothly even on a rainy day like today.

This made Ye Lao look at him more and more admired.

Ye Lao quietly arranged it.

In the eyes of outsiders, this set of methods was proposed by Ye Lao.

This is also Chen Ping's own request, he feels that he is too young to afford to create this method.

Besides, if this matter spreads, anyone will feel that there is something wrong with it.

A child who has never been in contact with water conservancy and civil engineering has created a set of measurement methods that can measure complex terrain on rainy days?

Who would dare to believe it?

When the errands heard about it, they didn't notice anything strange.

But after the students of the county school pondered carefully, their expressions became more and more excited.

It's not a low-level craft.

It is a secret technique that must be used in every large-scale civil engineering and water conservancy project.

With this precedent, it will be a hundred years of welfare!

Elder Ye taught them such a secret technique without reservation, which was tantamount to finding a stable retreat for them in the future.

If anyone can't get through the road to the imperial examination in the future, at least they can rely on this secret technique to find an errand to make a living.

The sensible students were full of reverence and gratitude to Ye Lao.

Chen Ping really didn't expect that the measurement method had such a side effect, which made everyone excited and very interesting.

But in the face of everyone's adoring gaze, Ye Lao felt a little ashamed, and his old face was red.

After all, this is a secret technique that has preempted the disciple, and even if there is a good reason, he can't feel at ease.

Fortunately, Chen Ping also saw the teacher's mentality, and said disapprovingly with a smile: "Why should the teacher care about these small details? ”

"What we are doing now is something that is related to the safety of hundreds of people in Yongshun County."

"For this purpose, all methods must be used, all means must be used, and the overall situation must be the most important!"

Ye Lao rolled his eyes angrily and said, "If you have the strength to play treasure, it is better to follow those county students to measure." ”

"By the way, didn't you say last night that there were still tricks to come up with? As long as this trick is made, you will be able to quickly find the most suitable outlet. ”

Chen Ping put away his obedient expression and said solemnly: "Teacher, please rest assured, my strange trick has already asked He Qingxuan to prepare." ”

"As long as the county students measure the elevation and distance of various places, and with my amazing tricks, they will definitely be able to quickly determine the flood outlet."

"At that time, as long as the teacher plans the location and route, he can start excavation."

As for what that trick was, Chen Ping didn't say it last night, he still wanted to sell it.

Ye Lao, in line with his trust in his disciples last night, did not delve into it even though he was in an urgent mood, so he waited patiently until now.

But this is all on the edge of the flood channel, Chen Ping is still selling Guanzi, Ye Lao glared.

His fingers bent slightly, and his arm was lightly raised, and a "murderous aura" that Chen Ping was very familiar with instantly struck.

Chen Ping sensed that something was wrong, hurriedly took two steps back, covered his little brain, and shouted repeatedly: "Qingxuan, quickly bring my sand table model!" ”

"Come and help!"

Ye Lao was stunned when he heard this, and muttered: "Sand table model? What's that? ”

When He Qingxuan and a servant came over carrying a huge object.

Ye Lao finally knew what the sand table model was.

It was nothing more than a three-foot square plank with layers of fine sand stacked on top of it.

But this fine sand has been preliminarily outlined, and the appearance, bends, dangerous shoals, and slope shapes of a river are seven or eight points similar to the Canghe River in front of you.

And on both sides of the river outlined by the fine sand, He Qingxuan had already drawn out a few thin lines, and the waterway was distinct.

Canghe has nine bends and eight bends, where it was impossible to see in the past, but now it is clear at a glance on this sand table.

Seeing this, Ye Lao's heart was like a dark light bursting, and his mouth suddenly opened!

In the past, in the matter of water conservancy, many problems caused by complex terrain and heavy mountains and mountains were suddenly solved.

If you could have thought of this wonderful method before, and shape those rivers and mountains with fine sand and gourds, where would there be so many problems?

During the spring and summer floods, it is time-consuming and laborious for the Ministry of Industry to repair embankments and build dams.

It is always necessary to send a lot of manpower to survey the river and explore the site.

Not to mention the consumption of silver taels, there are often casualties among officials during the investigation.

Why didn't anyone think of this sand table model?

After all, it's not some inscrutable knowledge, it's just a layer of unbroken window paper.

Under the huge joy, Ye Lao was full of emotion.

But when his gaze swept over the high hillside and the embankment at the source, his heart was shocked!

He hurriedly stepped forward and grabbed Chen Ping and He Qingxuan, and whispered.

"Hide it quickly, don't show it casually!"

"This thing is likely to kill you!"

Chen Ping and He Qingxuan looked dazed.

How can there be a murder, isn't that a great thing?

The teacher naturally would not deliberately intimidate himself, looking at the serious and tense face, Chen Ping hurriedly covered the sand table.

The three of them walked to a secluded place.

Ye Lao Fang scolded: "The hustle and bustle of the world is all for profit, and the hustle and bustle of the world is for profit, do you know how much benefit you have come up with!" ”

"With this, not only will the water conservancy work become simpler, but the march and battle will also save a lot of trouble."

"You and I are now without official protection, can a single royal county order really protect the benefits brought by such strange things?"

He Qingxuan was stunned.

Chen Ping was also stunned when he heard this, and realized that he was careless!

He just thought that this sand table model was just a thing from the bad street in his previous life, and it was not high-tech, so he took it out.

But it is forgotten that the truly precious things in an agrarian society are not just those high-tech.

Often high-tech things need a lot of conditions to support their use.

On the contrary, it is the kind of thing that is only separated by a layer of window paper, and once pierced, it can make a huge change in the society of the agricultural era is the most attractive.

Thinking of this truth, Chen Ping hurriedly said: "Teacher, then let's destroy the sand table and find another way to locate the flood outlet."

Ye Lao's expression was complicated, and after thinking for a while, he shook his head and sighed: "If we let the people of Yongshun County take more risks for our own calculations, the old man will have read the sage books for decades in vain." ”

He instructed: "This matter must not be passed on, but this method can continue to be used." ”

"You quietly move the sand table back to the hut room, and wait for me to record all the measurements one by one, and then you will add them to the sand table when you go back."

"When you find the exact flood outlet on the sand table, destroy it immediately!"

Ye Lao's reaction was extremely fast.

This method can not only quickly complete the flood discharge task, solve the danger of the people in the county, but also try to keep the secret of the sand table model.

......