- (Originally published in December 1945 "Enlightened Boy")

A deep well in the house

Is a salt well a well?

"A salt well is, of course, a well. ”

You're right. So, are salt wells the same as ordinary water wells?

"Of course it's different," you say, "the water in the well is light, and the water in the salt well is salty, and it contains salt." ”

Is there only one difference?

When you ask this question, you hesitate. Wells who have not seen. Since a salt well is also a well, is it any different from a water well?

There are many different places, and listen to me slowly.

Most of the wells are in the open air, but the salt wells are all in the house. The mouth of the well is the size of a bathing tub, but the mouth of the salt well is only the thickness of a soup bowl. Wells are six or seven meters shallow and one or twenty meters deep. The salt wells are surprisingly deep, and the shallowest is about 300 meters deep. It's deep? It's doubled by one or two times, and it's nearly a kilometer.

"It's so deep?"

It's so deep, it's not surprising. What is surprising is that the well, which is nearly a thousand meters deep, is all dug by hand.

"How can a person drill into a well with the thickness of a soup bowl?"

Yes, people can't get in, but they have to dig so deep. Isn't that surprising?

The earliest salt well

You have to start at the beginning. If we decide to dig a salt well, we must first ask an old expert in digging salt wells to choose a place to dig it. The old insider will tell us: where to dig the salt well, where to dig it, and then we can get the salt water.

"That old insider's eyes can see through the dungeon nearly a thousand meters deep?"

Who knows if he can see through it. Those people are as mysterious as Mr. Yin and Yang who looks at the cemetery. He went to a place where there were many salt wells, looked at a place, pulled out the grass on the ground, grabbed a handful of soil and sent it to the tip of his nose to sniff it, and nodded his head twice as if it was going on: "Okay, this is it, hit here and chisel down, and there is nothing wrong with guaranteeing." ”

"Is it really that accurate?"

Who knows! Whether there is salt water in the chisel down, and whether there is more salt water depends on our luck. However, I think that where there are many salt wells, there will always be some salt water underground.

"According to you, how did you choose the location of the earliest salt well?"

I've thought about this question too. But the more I thought about it, the more confused I became. It is said that the method of drawing well water to boil salt was invented by Li Bing in the Qin Dynasty. The legend is not entirely credible, but we can at least assume that salt wells were dug in Sichuan before 2350. On the tomb bricks left by the Han Dynasty, there is an image of drawing water and boiling salt.

"How did people know that there was salt water under the ground thousands of meters deep, and how would they know where to dig down to get salt water?"

Don't break the casserole and ask the end. Now that the location of the salt well has been chosen, let's invite the workers who sink the well and pick a good day to start construction and break ground.

That's the beginning

The workers first dug up the floating mud from the ground, and dug a large pit like digging a well. Before digging deep, the mud layer reached the bottom, and there were stones underneath. The masonry went down to the bottom of the pit and continued to dig. "Will you see the water when you dig down further?"

Of course, there is water, but also dug up dirt, chiseled stone chips. When the pit is shallow, water, soil, and stone chips are all carried out manually. When digging deep, a wheel axle was installed at the mouth of the pit, or by hand, and the water, mud and stone chips were brought out in an ancient mind.

"Isn't it very simple? Isn't it true that the workers dig down, and the things that are chiseled out, go deeper and deeper?"

It's not as easy as you think. When chiseled to a depth of more than 10 meters, the mouth of the pit can easily collapse. A collapse will not only undo the previous efforts, but also hurt people. In order to prevent collapse, when chiseled to a depth of 10 meters, it is necessary to build a stone circle one by one to block the surrounding soil and rocks that are not very strong.

The stone circle is hewn out of stones that are 3 meters square. From the bottom of the pit 10 meters deep, one by one. The two stone circles were also coated with lime to make it very close and prevent fresh water from outside the rings from flowing into the well. There are about 10 stone circles, and they are level with the ground.

"How thick is the hole in the stone circle?"

It's only the thickness of a large soup bowl. That is, about 30 centimeters in diameter. As soon as the stone circle was built, the deep pit that had just been dug became a well with a diameter of about 30 centimeters.

"Aren't you going to dig deeper?"

Of course, we have to dig down, thousands of meters of deep wells, and it takes a start.

"The wellhead is only the thickness of a large soup bowl, and if you have to dig deeper, how can you drill down to teach the workers?"

Workers don't go down the well anymore, they work on the surface.

"Do they use machines?"

They didn't -- no, I was wrong, they used rigs. I'll take you to see those weird drills and rigs first.

Big drill bits and big rigs

"What is this! Isn't it a weapon in the kingdom of adults?"

It's really a bit like ancient weapons, not only knives, guns, swords, halberds, everything, some with barbs, and some twisted into twists. Don't look at them covered with rust, the texture is pure steel. The wooden handle is made of the strongest green bar. The longest one was similar to Zhang Fei's Zhangba Snake Spear, and the heaviest one was twice as heavy as Guan Yun's long Qinglong Yanyue Knife.

"Are these drills?"

You're right, these are drill bits and come in more than 200 different styles. The drilling rig is a very large runner, and the workers call it a "big car".

"How big is that cart?"

The cart is dragged by oxen and has a diameter of 5~7 meters. The axle of the disc stands upright on the ground and is nearly 3 meters high. There are also people who step on them, which are relatively small, with a diameter of less than 3 meters, and the axle of the coiling car rests horizontally on the shelf, with a width of 2 meters.

After the stone circle was built, the workers put the large plate on the side of the wellhead. The function of this cart is no different from that of an ordinary water well. It is all up to it to draw salt water from behind, and it is all up to it to dig a well in front of you.

"I think we'll have to use a rope. ”

By the way, use a rope, use a strange rope. They cut the very thick bamboo into slabs about 7 centimeters wide, and then connected the slabs one by one, and tied them tightly with miscanthus linen.

Lick and lick

The worker wrapped the rope around the cart, and then chose the most suitable one of the more than 200 drill bits, tied it to the other end of the rope with the main linen, and slowly hung it down from the stone circle to the end.

So, the workers pushed the crank back and forth, the rope was lifted and released, and the drill bit was chiseled down again and again.

"How can those iron tools be chiseled into broken stones without a sharp edge?"

yes. Actually, it's not chiseling, it's just pounding again and again. Didn't I say that the drill bits are very heavy, and they crush the rock with that weight.

"How do you take out the stone chips that have been scooped down?"

There is a little bit of water in the ground, and the stone chips are mixed with the water to form mud, and it is just drawn out like salt water in the future.

"Is it just like that, straight to a depth of thousands of meters?"

Isn't it? When you dig to a depth of about 100 meters, you have to dig down wood and bamboo. Because the shallow rock texture is not very strong, there are many cracks, and fresh water will seep into the well through the cracks, so it is necessary to use wood and bamboo to block the water. Below 100 meters, the rock is almost monolithic and hard, and there is no fresh water seeping in, so there is no need for wood and bamboo. Therefore, as soon as you dig into the deep hard rock, you have to go down to the upper layer of wood and bamboo.

"What is wood and bamboo, is it wood or bamboo poles?"

It is a bamboo pole-like cylinder made of wood, and it is often made of straight green poles or cypress. The timber was cut in half, hollowed out in the center, and then put it together, tied tightly with ramie, and covered with tung oil lime, which looked like a bamboo tube? The inner diameter of the long tube was less than 33 centimeters. The two ends of each section of the long cylinder have close tenons, which are connected one by one. The place where the tenon is jointed should also be embedded with tung oil lime. The attached wooden bamboo is lowered from the stone circle, and the lower end is connected to the hard rock, and the upper end is connected to the stone circle, which blocks the fresh water outside the well. After that, the wood and bamboo will often be damaged, and the salt worker says that "the well is leaking", so the damaged wood and bamboo must be pumped up and replaced with a new one.

I got down the wood and bamboo, and chiseled down as usual, again and again, and so on, for 5 years, 10 years, 15 years, and 20 years...... Dig straight to the bottom of the well and salt water comes out.

"How long will it take?"

It was a matter of luck - all the well digging workers said so.

Buckets without a bottom

Salt water came out of the bottom of the well. But the well is so deep, do you think, how can we draw up the brine from the bottom of the well?" "It's very simple, use a bucket ......."

You have forgotten that the mouth of the well is only the thickness of a large soup bowl, and ordinary buckets cannot go down. To draw water from the salt well, there is a special bucket. The bucket was thin and long, made of two to four thick bamboo poles with knots. What's even stranger is that such a long bucket has no bottom. "If there is no bottom, how can it hold water?"

At the lower end of the long bucket was a round trap made of cowhide. The bucket reached the bottom of the well and was inserted into the brine, which washed the trap away and went into the bucket. When the bucket is lifted up, the salt water in the bucket presses down on the trap and it doesn't come out. When the bucket is lifted to the ground, there is no need to turn it sideways, just use an iron hook to lift the trap upwards, and the salt water will flow into the sink with a roar.

"It's a clever way. ”

Yes, the bucket is so long, it would be too much trouble to pour water sideways. The deeper the salt well, the longer the bucket used, one or twenty meters long, which can draw more than one load of salt water at a time. Shallow salt wells use shorter buckets, and they can pick up more than half a load at a time.

"It's not easy to hold on to the bucket so long that it doesn't fall over. ”

So each salt well has a very high wooden shelf. In the center of the wooden shelf is a long, thin cage. The bucket rises up from the well, and the top is pierced into the cage, and it does not fall down. When we arrived at the place where the salt wells were concentrated, we saw high wooden shelves like dense forests, and under each wooden shelf was a salt well.

Wring the bucket up

Twist the bucket together, also with a piece of rope, and also with a coiled cart.

In the deep salt wells, the axles of the crank are upright and are pulled by oxen, and each cart uses one, two, and three oxen. The oxen pulled the cart in a circle, and it took forty or fifty turns to wring a bucket of brine from the bottom of the well to the surface.

In the shallow salt well, the axle of the coiling car is horizontally framed, and it has to be stepped on by people. Or get into the crank and spin like a mouse on a wheel.

The cart and the salt well are all in the house. So production is not affected by the weather.

The salt water is drawn up, and the salt can be boiled. Some salt wells are far away from the salt boiling factory, and the salt water is usually transported to the salt stove with continuous bamboo pipes.

A fire that never goes out day and night

"Did the brine just flow straight into the pot?"

You are mistaken. "Salt stove" is a manufacturer of boiling salt, and everyone calls it that. The brine drawn from the well is yellow and turbid, and it must be clarified and filtered before it can be put into a pot to boil.

The fire under the pot is not extinguished day and night, burning coal or wood. Workers are constantly pumping fuel into the stove door. The roaring light of the fire illuminated the faces of the workers. On the cooktop are rows of pots with varying shades of brine in the pots. The diffuse water vapor filled the room. The workers moved the salt water from the light pot to the thick pot, and kept stirring the salt water in the pot. When the water gradually evaporates and dries, the thick brine pot forms white salt.

"How long does it take to boil for the water to evaporate?"

Not necessarily. The brine itself can vary greatly from thick to light. There are also large and small pots. It takes at least a day and a night to get out of the salt. In the pot where the salt water was thickest, the water almost evaporated, forming snow-white salt grains. The workers scooped out the salt, put it in a basket, and poured a few scoops of water.

"Pour water on it, won't the salt dissolve?"

Salt doesn't dissolve. Salt contains a lot of impurities, including magnesium chloride and calcium chloride, which are easier to dissolve than salt. When the snowflake salt is put in a mold, it is strong and becomes a brick piece by piece, which is called "brick salt".

"Aren't you talking about Ba Yan?"

Brick salt is not basalt salt. The boiling method of Ba salt is slightly different, and it takes at least two or three days to boil before the salt comes out. The fire also burns day and night. As the water in the pot gradually evaporates, add salt water at any time to let the salt slowly condense from the bottom of the pot and become thicker and thicker. Until the end, the whole pot is clumped into a large piece, and the salt is shoveled down.

"Which salt is good?"

Each has its strengths and weaknesses. Ba salt has less moisture and is easy to handle, but there are many impurities. Flower salt and brick salt have more moisture, but they are relatively pure. Flower salt can only be carried by loading baskets, and brick salt is as convenient as Ba salt. The mountainous roads in the Sichuan-Tibet-Yunnan-Guizhou region are rugged, and the transportation problem must be considered.

Everything needs to be improved urgently

"Are you telling the truth?"

Why is this not the truth? When you ask this, you must think that what I am saying is too bizarre, unlike the modern things of the 20th century. However, the salt wells in Sichuan are indeed like this, and they may not be any different from 2,000 years ago, which is really too old. It will take a decade or two to dig a salt well, and we don't have the patience to wait. Why not use machines instead of oxen and manpower to draw salt water? The biggest cost of boiling salt is fuel. How to save fuel is also a very important issue.

"In this way, everything needs to be improved. ”

I see it this way, too, everything needs to be improved urgently.