Before leaving, Wu Yanzhi reported to the emperor for approval and recruited six inspectors to supervise the mining and smelting of copper and iron in various regions.

Wu Zetian was naturally overjoyed to see that hundreds of thousands of catties of copper, zinc, and more than one million catties of iron had been added last year. She still felt that there were fewer six inspectors, so she naturally easily agreed to Wu Yanzhi's request.

The daily business of the copper and iron envoy, of course, is still handed over to Sun Heng to be in charge In addition, he has promoted Cui Yu to the rank of pusher; This magistrate is one level higher than the inspector.

On the third day, five miles outside the Hui'an Gate in the north of the city, the flag was unfurled, and the drums shook the sky!

Today is the official departure day of Wu Yanzhi. Wu Zetian personally ordered Yang Zaisi, the secretary of Tongping Zhang, to see off Wu Yanzhi outside the West Gate.

As mentioned earlier, this Yang Zaisi has always been a person who has been circling around those in power, and he is a man who sees the wind and steers! He looked at Wu Yanzhi in military uniform, and said with a flattering smile:

"If Wu Lang goes, he will definitely wipe out the thieves! When he returns, he will be crowned king! When the time comes, the contemptible people will come to pick up the wind for Wu Lang! ”

"Yang Xianggong has a good reputation! I hope it can really be as Yang Xianggong's wish! At the time of triumph, he brought a few catties of century-old Korean ginseng to Yang Xianggong! ”

"Thank you Takerou! But it doesn't have to be. Wu Lang's victory is what I want......" Yang Zaisi said.

The two talked a few words, and Yang Zaisi said goodbye and left.

"General Li, you lead the troops first, and I will arrive with the personal guards immediately,......" Wu Yanzhi ordered.

"Yes".

……

Wu Yanzhi gave a few words of admonition to the guards.

His bodyguard consisted of seventy men, a squad of fifty cavalrymen, and twenty musketeers. Wu Yanzhi allocated a team of fifty cavalry as his own personal soldiers, led by his nephew and lieutenant Wu Shouping. After several months of training, Wu Shouping is very familiar with military orders, military etiquette, and military law!

Of course, Wu Yanzhi intended to cultivate and promote him. Generally, many children of the royal family are reluctant to go on the expedition, after all, in ancient times, it was very risky to join the army.

He looked at his guards, especially the twenty musketeers, and was delighted. This is a musketeer, and the gun has a bayonet on it. They were all selected guards in Raozhou, and they had been following them for months.

Yao Kuan, as a school captain, is now in charge of their team. One of them, Deng Tong, a very shrewd guard, who had made meritorious service in the last attack on Feiyun Village, had already been awarded the rank of lieutenant from the ninth rank of the loose official accompanying Rong.

He was promoted by Wu Yanzhi to be the deputy of the team this time, and he and Yao Kuan jointly managed these twenty people, just two fire people.

……

After gathering all the teams in Chang'an, Xiao Huan felt that there was still something to do, so he asked Li Quanyi to lead the main force north to Taiyuan first.

He himself led five hundred cavalry and walked the road to Yanzhou. He's going to go there to check for oil, and Yanchang County is one of the first places in our country to produce oil.

After ten days of walking, they arrived in Yanchang County. Arrived at the county inn, as usual, the county magistrate and others came to greet Xiao Huan and his party.

At dinner in the evening, Xiao Huan asked the county officials how the local production of paraffin water (oil) was.

The county magistrate replied: "In the past, there were many springs of resin water gushing out of this county, and the people used to light lamps. But now there is almost no outflow of their own, and they all dig their own wells. ”

"Digging a well? How deep did they dig the well? Xiao Huan asked.

"It's not easy to talk about this, there are a few zhang and twenty zhang."

"Can you fight twenty feet? How did you fight? Xiao Huan was very interested.

"It is necessary to build a shelf one or two feet high, and then drop a drill bit on it, use the drill bit to strike, and after breaking the stone such as a drill, you can take it out with a special claw. Generally, it takes several months to fight dozens of feet! ”

When Xiao Huan heard this, this speed was still very fast. I'll have to go to the site tomorrow to see them and help them with some guidance. A simple oil refinery was built here. Petroleum is distilled to produce gasoline, kerosene, and diesel.

Diesel and kerosene can be lit, so gasoline can be of great use, and it can also be used as weapons on the battlefield. This can be a very advanced weapon, not much less powerful than that gunpowder.

The next day, under the leadership of Wang County's order, the group rushed to Gaojia Village, not far from the county post house.

"General Wu, this is the main aquatic production area of stone resin, which can produce more than a thousand stones a year. It's a great thing to use for lighting. It is also often used now, but the smoke is a bit loud, and many people don't like it very much. ”

Xiao Huan heard that you were burning crude oil, which had not been smelted, and of course the smoke was very large. It would be much better if it was replaced with smelted kerosene and diesel.

The group arrived at a small oil production site.

When those migrant workers saw a large number of officers and soldiers and officials coming, they were very surprised and nervous, and immediately put down their work and waited for the officials' questions.

There was a village leader accompanying him, and he called an old man in his sixties: "General Wu, this is a senior old man, he has been digging wells here to produce stone grease water for decades." Brother Gao, hurry up and meet General Wu. ”

"Grass people, see General Wu." He had never seen such a large formation in his life, and he was a little panicked, and his face was dripping with sweat.

"Uncle Gao is exempt. Dare to ask my father-in-law, how much paraffin water can your well produce in a year? How much can a bucket of paraffin water sell for? Xiao Huan asked.

"Returning to General Wu, the output of each well is also different, a good well can produce more than 100 stones a year, and a worse one can only produce a few dozen stones.

This price is very low, a bucket is only ten cents, and after removing the taxes paid, it is barely enough to support the family. ”

Xiao Huan asked about the situation again, then walked around again, and then said to Qi Xuan:

"Judge Qi, I think it's very good to build an oil refining workshop here. It is estimated that the construction of this oil refining workshop will only cost a few hundred yuan. ”

Qi Xuan nodded and said, "This oil refining workshop doesn't cost much, but it's a bit troublesome to transport this refined oil out, and it only depends on mules and horses." ”

………………………………………… Dividing line ......................................................

Here we would like to introduce the distillation technology of petroleum.

It usually includes three processes: 1. Crude oil pretreatment: that is, the removal of water and salt from crude oil. 2. Atmospheric distillation: the straight-run fraction of gasoline, kerosene, diesel, etc. is distilled at close to atmospheric pressure, and the residue at the bottom of the column is atmospheric residue.

Taking a certain petroleum as an example, the boiling range of gasoline is 30~210C; kerosene boiling range 180~310c; 350?410c；

Simple petroleum distillation is carried out according to the different boiling points of various oils.

The oil smelted by Xiao Huan does not need to be of high quality for the time being, and is mainly used as a fuel for combustion, as a weapon used on the battlefield. Therefore, the difficulty of smelting is not very high.

It is to make a still and control the temperature, which is more technical. In particular, the control of temperature is directly related to the quality of the oil.

Of course, if it is the oil used in the machine in the future, the quality requirements for the oil will be higher.