In the early morning of the tenth day back to Baihogang, Han Qian woke up very early, the sky was not yet bright, and the light in the house was even darker.

In order to avoid the leakage of the news of his departure from Xuzhou and his whereabouts, all the secret letters were written in ciphertext, passed down layer by layer, and needed to be translated before they could be read.

This secret letter was translated overnight by Xi Ying last night.

Everything is fine in Xuzhou, and the holy decrees and edicts about the alliance between Chu and Shu have also been copied to Xuzhou.

The terms of commerce and trade between the two Shu in the Qianjiang Passage were specifically enforced by the Wuchuan Salt and Iron Yuan, which was nominally under the jurisdiction of the Hunan Transit Envoy, but was actually controlled by Xuzhou for the time being.

The Yuzhou side has also sent officials over to further discuss the connection between the two sides.

Xuzhou has also further strengthened the renovation of the Caojingling Post Road, which should be widened to the standard of five feet by the end of the year, allowing vehicles and horses to barely pass.

These are aware of the huge consumption of money and food in Xuzhou, and they can only squeeze out limited money and food in a short period of time to support the construction of the Chishan Society.

A more critical piece of news is that a small well was successfully drilled to a depth of 30 zhang in Wuchuan.

The existing salt wells in Sichuan and Shu are all large shallow wells.

This is mainly due to the technical limitations of drilling in the world.

The deepest salt well is 30 zhang deep, but the diameter of the wellhead is more than 60 or 70 zhang long, which shows how huge this so-called large shallow well is.

Not to mention anything else, how much manpower and material resources do it take to dig such a deep and large salt well?

Not to mention the later maintenance.

The two salt wells in Wuchuan and the newly discovered two salty springs are located in a mountain range on the east side of the Qianjiang River, which indicates that there must be rich salt mines or salt brine resources under this mountain ridge with complete geological structure.

However, the problem lies in the fact that in this part of Wuchuan County, the shallow surface layer that flows through the cracks in the rock layer above the bedrock, and the salt brine that even flows directly out of the surface to form a salty spring, is extremely limited.

As a result, it seems that the salt resources in Wuchuan are very limited, but in fact, with the current drilling technology, more salt brine cannot be extracted.

If you want to extract brine on a larger scale, you need to improve drilling technology.

Directly open up the rock formation, and use small deep wells to directly exploit the salt brine resources located under the bedrock and deep in the rock formation.

Of course, Han Qian only provided drilling ideas for using the later Shidun drill to impact the broken rock.

There is no epoch-making technical content in this idea, but under this idea, to develop the tools at hand, and to ponder and form a complete set of drilling and mining supporting technologies, is what Chen Jitang leads the engineering school to do.

The preliminary research took three or four months, and it was only in early April that the field drilling test was officially carried out in the Wuchuan Mountains.

At present, it took one and a half months to successfully drill a small well with a depth of 100 meters in the mountains on the east bank of the Qianjiang River, breaking through the depth limit of the world's large wells.

If this technology is transmitted to Shu, Han Qian believes that the output of well salt in Shu can be increased by one or two times or even higher in three or five years on the basis of the existing manpower.

"What's the matter, so excited?"

Xi Ying got up a little later, pushed the door and saw Han Qian standing in front of the window with a smile, and asked.

"The secret letter you translated last night, don't you know that Chen Jitang successfully drilled a 100-meter-deep well in Wuchuan?" Han Qian asked.

"What's the big deal about this, isn't it that a new salt spring hasn't been dug yet? It is likely that such a large amount of manpower and material resources will be wasted. Xi Ying asked.

Xi Ying knew that the Engineer School convened people to drill a small well thirty zhang deep in Wuchuan Fei Lao's nose, but she did not successfully mine the salt brine, she still felt regretful in her heart, but she did not think deeply about what the continuous improvement of drilling technology behind this practice represented.

This gap between vision and knowledge, even if it is Xi Ying, cannot be made up by personal ingenuity.

"How can it be in vain?"

People in the dream world remember that during the Song and Ming dynasties, the people of Sichuan and Shu used small deep wells to not only extract salt brine and natural gas from the ground, but also exploited oil in Bazhong and southern Sichuan!

Han Qian was about to have a good chat with Xi Ying about the significance of this new drilling technology, and He Liufeng and Lin Sheng knocked on the door and walked in.

Lin Shengyu reports:

"Yesterday after nightfall, a group of men and horses sneaked into the woods west of Whitehoof, but they lurked in the woods all night without moving. We didn't dare to startle the snakes, and we didn't know exactly how many were lurking. However, it didn't rain last night, and I'm going to make a detour to the northwest to search for it, and I should be able to tell from the footprints they left behind......"

Even if they can use the telescope, they can observe that there are anomalies in the forest to the west, and they can also see some faint figures, but if they want to confirm the specific number of ambush soldiers, the simplest and most direct way is to directly send troops and horses into the woods to make a tentative attack on this group of ambush soldiers.

However, if you don't want to startle the snakes, as long as you can find the route where they lurked, you can also judge a rough idea from the clues they left behind.

Feng Yi had just gotten the news at this time, and walked in with Guo Rong, Feng Yi, and Kong Xirong, and said, "They didn't launch a sneak attack last night, and they continued to lurk in the forest, obviously they still want to take advantage of the night to continue to transfer more people, and then catch us off guard at once." ”

"Don't send people out to search, as if you don't know anything. Since these people have made up their minds to only dare to attack us, they actually have nothing to fear. I'm afraid that they're attacking from the north and south sides now! Han Qian said.

Feng Yi: Think about it, too.

Han Qian also instructed Lin Sheng and He Liufeng, who were specifically responsible for the construction and defense of the camp: "The camp is tight inside and loose outside, don't have other extra actions, and wait until tonight." Except for the main personnel, ordinary congregants and families should not issue warning signals in advance, lest people be panicked and dare not sleep at night, and when they really want to meet the enemy, they will fall into the trap of the enemy. ”

Han Qian thought to himself that if there were more men lurking in the forest to meet them tonight, then when they attacked, it would be at least after the second half of the night or the early morning of tomorrow.

"Do you transfer out first, the enemy army is really going to raid in, and then there will be chaos, I'm afraid that there will be a mistake." Lin Sheng said.

"I don't have the guts to do this, it's really underestimated by the enemy," Han Qian waved his hand and told Lin Sheng and He Liufeng what they should do, don't persuade him to leave in vain, and said, "If the enemy just makes up his mind to sneak attack from the west, there will be chaos on this side of the camp." ”

As a last resort, Han Qian would not let Kong Xirong lead the guards to kill the enemy immediately, this was to avoid his whereabouts from leaking, and also to avoid attracting more large-scale attention at this time, but the guards and horses had to stay in Baihogang just in case, how could they escort him away at this juncture?

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During the day, the camp was methodically reinforcing the defenses on the north and south sides.

Due to the narrowness of the Baijiegang Mountain, a stable stream cannot be formed in the mountain, but there are still natural dry ditches in the mountains that leave rainwater washed along the valley terrain during the heavy rainfall season.

The villagers who used to live in Baijiegang also dug ditches between the dry ditch and the lake to the east, which on the one hand could divert water from the lake to irrigate the farmland on both sides, and on the other hand, during the heavy rain, the mountain torrents could be drained from the dry ditch and the ditch under the mountain into the lake in time.

Even from the houses that remained, it can be seen that before the war, a small number of villagers lived in the fishing village east of Shirajeoka, but they mainly lived by fishing, and the ditches and other water conservancy facilities under the mountain to the east have long been in disrepair.

This is also a microcosm of the significant reduction in the population of Jianghuai more than a decade ago.

For example, Shiliang County, which is mainly located on the Huze Plain, had a prosperous population of nearly 100,000 in the prosperous era of the previous dynasty, but before the Jinling Incident, the number of people dropped to less than 20,000, which is worse than that of a remote mountainous county such as Jinhe County in Sizhou.

These days, the camp is on the north and south sides, and the people are concentrating on clearing an abandoned ditch to divert water from the lake.

In this way, the land connection between the north and south sides and the outside world is blocked, and the only way to enter and exit is through two simple suspension bridges.

On the east side, in addition to the extremely dense reeds, the beach is wide and shallow, and it is difficult for even a flat-mouthed shallow-bottomed boat to get close.

In the past two days, Lin Sheng and He Liufeng organized people to dig a row of wooden piles in a dry ditch halfway up the mountain in the east, and then filled the side of the wooden piles with earth and stones, thinking of building a simple earthen dam five or six feet high.

Waiting until it rains and accumulating rainwater can not only irrigate the slopes on both sides, but is also a threat to any large-scale enemy forces that try to enter the camp from under the earthen dam.

In addition to the guard towers, they will also repair walls along dry ditches and ditches to further improve the defense system; Build a boardwalk through the shallow silt beach and extend the deep water to facilitate the entry and exit of ships.

In this way, the foothold of the Akayama Society here will be gradually improved.

The day passed quickly, the sky was dark, the weather was cloudy, the full moon was covered by dark clouds, only a corner was exposed, and the sky and the earth were barely bright enough to see.

Han Qian also went up the mountain after dark, squatted in the woods, and took a telescope to observe the woods in the west.

The woods stretched out from the foot of the hill, about two or three miles deep, and further west were deserted fields, where a few small camps of displaced people gathered, and bonfires lit at night were clearly visible.

If it weren't for the fact that the mirror could faintly see the northwest direction, there were shadowy people and horses moving towards the woods to the west, and it would be difficult for the naked eye to detect the slightest abnormality in such eyes.

"The new group of people and horses have more than 30 war horses, but they can't hear the neighing of horses at all, maybe they are the elite of Anning Palace or Huaidong." He Liufeng frowned, leaned over and said.

The Anning Palace and the exile forces controlled by Huaidong in the shadows could launch a surprise attack on them, but before they really made contact, they couldn't even figure out whether the enemy in front of them who intended to sneak attack them was from Anning Palace or Huaidong.

Of course, looking at the enemy soldiers lurking in the woods, they were more cautious than they expected, and Han Qian and the others were still more inclined to think that it was the men sent by Huaidong, especially the small group of men and horses that were sneaking into the woods to the west at this time, it was more likely that Huaidong had directly sent the elite of the lineage from Chuzhou......