Wang Mao, the blacksmith foreman, ordered people to move a wooden box, which contained long and short weapons and bows and crossbows that had been packed. Li Qi, Cao Xin, and the ordnance supervisor Shaocheng Guo Kai and others began to conduct random inspections with great interest.

Cao Xin took out a steel crossbow with a strange appearance from the wooden box and assembled it with Wang Mao.

"Your Majesty, this is the newly developed crossbow according to your requirements," Wang Mao handed Li Qi an assembled steel crossbow.

I saw that the crossbow arm was about three feet long, and the grip was about three feet, which was not convenient to carry. The bowstring was about twice as thick, and an iron ring was fastened to the front of the crossbow arm with a cowhide rope, like a stirrups. In addition, the chute for the bolts was closed from top to bottom, and the bolts were loaded through the round hole in front of the arm.

Three pulleys were also fixed at both ends of the crossbow arm, which made it possible to increase the length of the crossbow string to increase the tension.

The energy storage of spring steel is not very good, and the crossbow arm of this steel crossbow still needs composite materials such as angle ribs, and the production method is the same as that of the composite iron tire bow, which is very complicated and expensive.

Li Qi pushed the soles of his feet into the pull ring, and then bent down and pulled the crossbow string up with both hands by pulling the lever hard, almost using the strength of his whole body, before he struggled to jam the crossbow string on the crossbow handle.

The shaft of the crossbow arrow is shorter and thicker than that of the feather arrow, and it does not have a balanced tail, so it can only be fired directly.

"Well, this locktooth lever is very convenient for winding, and you can see that the craftsmen are attentive." Li Qi said to Guo Kai who was standing beside him while winding the steel crossbow with his own hands. Although it was still a little difficult to wind, before the winch was developed, it could only be used in this way.

Li Qi stuffed a crossbow arrow with a round wooden pole into the arrow hole from the front, held the steel crossbow flat with both hands, and aimed at a big tree more than 20 zhang away. There was a slight pause, and then the bracket was pulled. Just listening to the sound of "bang", the ringing sound of the bowstring just sounded, and there was an extra yellow-brown arrow shaft on the trunk of the big tree more than 20 zhang away, which was three inches into the wood.

"Huh? It seems to be more powerful than the original Tension Crossbow, and you don't have to sit on it! Li Qi's personal general, Yuan Ren, exclaimed, and also became interested. He took the steel crossbow from Li Qi's hand, and after loading the crossbow arrows, he grabbed the handle with one hand, squinted one eye and shot an arrow directly from the opening of the aiming gauge above the board machine to a column more than ten zhang away, and then said without looking back: "This thing is good, it is much more advantageous than the original crossbow, the hands are much more stable, and this iron frame is very smooth, and it does not require much finger power." ”

Li Qi rolled his eyes and looked at Yuan Ren and Kang Tai: "This is for the infantry army, your subordinates are all cavalry, you don't need this thing!" ”

The caravan used the cloth to exchange for a lot of dried raw cowhide from Yunzhou, which was very tricky to deal with.

The herdsmen on the steppe handled the skins in a primitive way, using fermented bran and coating the surface of the fresh skins after fermentation, and then performing simple degreasing and blending. Rawskin, on the other hand, is a dry skin that has hardly been processed, and this thing is as hard as iron, and ordinary merchants are reluctant to buy it, so the price is very low.

Li Qi allowed the caravan to buy large quantities of this untreated raw cowhide and raw sheepskin, because he knew that soaking it in caustic soda would restore the elasticity of the dry skin.

Anyway, for the sake of the iron black pigment, he had to pound out the caustic soda first.

This is actually a simple experiment in junior high school chemistry.

Those who are familiar with the history of chemistry know that chemistry originated from the alchemy of Taoist priests and the alchemy of Western alchemists.

The Taoist priests of the two Jin Dynasty liked to refine and consume this various "elixir" containing a large amount of heavy metal poisons, which led to the emergence of some famous fools recorded in the history books among their descendants.

After lunch, Li Qi came to the workshop in the backyard of the palace, and then instructed He Jian, the housekeeper of the palace, to bring the clarified lime water into the room with a few servants. He Jian has been Li Qi's companion since childhood, and now he has learned a lot from Li Qi.

"Slowly pour the small jar of alkaline noodles into the water, and slowly stir it with a wooden stick as you pour it...... Yes, that's all, don't worry! Li Qi was guiding He Jian to operate. Alkali noodles are the soda ash used in steaming cakes, which has a large number of trona ore in Yunzhou and later Inner Mongolia, and after removing impurities, its main ingredient is soda ash, that is, sodium carbonate.

With the input of soda ash, the slightly yellowed water of the original semi-porcelain basin slowly became turbid, and it became more and more turbid with the agitation of Kangjian. In addition, the water in the porcelain basin is slightly heated because of the chemical reaction.

The people standing on the side craned their necks and looked straight at the sight......

Seeing that the reaction was almost over, Li Qi asked He Jian to stop and wait for the white substance to settle down.

"He Jian, how to make lime water before, you all remember clearly?" Li Qi looked at He Jian, his name has the word "alkali", and it is just right to do this job now.

He Jian nodded, "You know, you need to be careful to add hydrated lime to the water, and you need to keep stirring to prevent boiling!" ”

Limestone is calcium carbonate, and calcium oxide, that is, quicklime, is obtained after calcining limestone. Then the calcium oxide is reacted with water to obtain lime water for brushing the wall. This aqueous solution is calcium hydroxide, also known as hydrated lime, which is the previous basin of lime water. Then, soda ash (sodium carbonate) is added to it, and after the reaction, an aqueous solution of sodium hydroxide and calcium carbonate (limestone) are obtained.

Sodium hydroxide is the so-called caustic soda or caustic soda. This caustic soda solution only needs to be evaporated to dry the water to obtain caustic soda. Caustic soda and soda ash, together with sulfuric acid, hydrochloric acid and nitric acid, collectively known as three acids and two alkalis, are widely used in the chemical industry and are the basic raw materials of modern inorganic chemical industry.

"This lime water reacts with soda ash to get caustic soda water, and if the water is steamed and dried, you can get caustic soda, a very powerful thing that can erode through the iron bucket." Li Qi said that in fact, caustic soda is not made into a concentrated solution, and the corrosiveness is not so serious, and this kind of thing is often used as a desiccant in various commodity packaging in later generations.

"Sanbao, do you understand what this is doing?" Now that the water has basically completely settled, the water has become clear again, but a layer of white lime has formed on the bottom of the basin, Li Qi looked at the little guy who was half-opening his mouth and asked with a smile.

"Your Majesty, are you making lime?" The little guy looked at Li Qi with a puzzled face, this has gone around a lot, didn't he go back to the same place, and he knew that he would be able to throw a handful of limestone into the water.

"Mallet, what do I do making quicklime, I want this basin of water, I just said ......"

"Oh, you know, it's caustic soda!" Sanbao patted his head.

"Alright, now find a few small pieces of dried cowhide and soak them in the water, and you will see the effect in a few days......" Li Qi continued to command. In fact, this was the first process of processing dried cowhide, and in later generations, many black-hearted merchants also used this method to process dried aquatic products......

After the hides are melted, they need to be soaked with dilute sulfuric acid to make the dry skins soft again.

The preparation of dilute sulfuric acid is also simple, that is, the red smoke (sulfur dioxide) discharged by pyrite during calcination is filtered through a water tank to obtain sulfurous acid, and then it is opened to the air for secondary oxidation.

It's simple but very simple, that is, its production efficiency is outrageously low.

After soaking the pyrite powder in caustic soda water, and then sending it to the calciner for roasting, the product is no longer iron red, but becomes a slightly graying iron black pigment......

Maybe soon, in their own dyeing workshop, there will be another color of woolen cloth.

The grassland people, especially the Qiang people, think that black is more advanced, and as a result, the sales price of black cloth with almost the same cost is actually one percent higher than that of dark red cloth......