To tell the truth, Yang Wenli had never seen a ballista in his previous life or in this life, so he designed it completely by his own imagination, which was significantly different from any kind of ballista in the world.

His ballista, with the exception of the large recurve bow, was made of steel, resembling a mortar with wings, very slender and very simple.

It is not a round barrel like a mortar, only half of the barrel-like slots, and the front wing part is designed in a T-shape, which is a little thicker, and the rear part is too slender, and the whole is a big T-shape.

Yang Wenli asked Yang Renri to make a large recurve bow, the bow body part is different here, the bow body is set under the groove, in a U-shaped, there is a triangular support on both sides of the groove, which can strongly support the tension of the bow arm.

The U-shaped bow body makes the bow arm part flush with the groove, and at the bottom of the groove is a rope tightener and a crossbow machine.

There is a fixed rope on the rope tightener, there is a forked hook in front of the rope, when firing, the hook on the rope hooks the bowstring, the soldier can use the steel rod to turn the rope tightener, slowly pull the bowstring, hang it on the crossbow machine, and then you can loosen the rope tightener and remove the hook, so as to complete a launch preparation.

The principle of the ballista is so simple, because of the use of steel parts, so all have to be cast, and because only Yang Wenli knows the principle, he can only use the lost wax method to make steel molds.

It took ten days for Yang Wenli to make various molds with the help of slave soldiers.

"Shh......h All right! Renri, you immediately arrange someone to cast parts, first cast a set, and try the effect. Yang Wenli sighed and instructed Yang Renri, who had come to understand the process.

"Yes," Yang Renri bowed deeply and agreed.

It didn't take much effort to cast, just set on the stove, and Yang Renri immediately commanded his slave soldiers to start busy.

Yang Wenli, who was sitting on the side and resting, watched them busy, he was actually nervous in his heart, this is a ballista he designed himself, there is no precedent, I don't know if it will work?

Two hours later, Yang Renri ran over to report to him with sweat on his head: "The big boss has been cast." ”

"Let's go, let's go test the gun, it's okay, that's it." Yang Wenli stood up, threw away the apprehension in his heart, and said fiercely.

Yang Wenli's ballista is combined, like a light machine gun bracket style bracket, the magazine is resting on it, fastened with a steel bolt, there is no nut, and the use of a circlip makes the assembly simpler, but the tightness is a little worse.

The slave soldiers took a large recurve bow, put it on according to the U-shaped groove, fastened it with a steel bolt, installed a rope tightener and a crossbow machine, and a simple ballista was successfully assembled, and the whole process took only more than two minutes.

Then, Yang Wenli took matters into his own hands, put on the rope, hooked the hook to the bowstring, and turned the rope tightener with a steel rod, only to see that the tightly collapsed bowstring was pulled apart by him little by little, until he crossed the crossbow machine, he started to loosen the rope tightener and hook, and let the bowstring hang on the crossbow machine.

Yang Wenli went to the ground again and randomly picked up a stone of suitable size and put it on the crossbow machine. He didn't take aim, so he decisively pulled the trigger, only to hear a bang, and the huge tension of the bowstring threw the stone into obscurity, leaving only the bowstring humming and trembling.

The ballista is not a crossbow arrow, and it can't be accurate, because the stone can't be standard, so Yang Wenli just tried it casually to see if it could be fired successfully.

"Ren said, you continue to experiment, test the maximum range, the nearest range, and summarize a set of quick combinations, rapid firing operation steps, if there is no problem, tomorrow immediately cast a large number of them.

The fleet can't wait too long, so hurry up, you know? ”

"Obey orders" Yang Renri's firm promise without nonsense.

It would take a few days to cast the ballista, but Yang Wenli didn't want to waste this time, so he began to polish the optical materials of the telescope.

Early telescopes were Galilean telescopes, which were generally monoculars and simple in construction. Yang Wenli wanted to develop the Kepler telescope, and later binoculars were like this.

The difference between these two types of telescopes is the difference in lenses, the Galilean telescope is composed of two concave lenses, while the Kepler telescope is composed of two sets of convex lenses and two sets of prisms.

In ancient times, the conditions were very simple, and there were no advanced and precise instruments to measure and polish lenses, so Yang Wenli used the lost wax method to first cast two kinds of convex lenses and prisms, and then polished them.

As we all know, glass has a high hardness coefficient and is difficult to polish, especially by hand.

This is where the manual mill designed by Yang Wenli comes in handy, converting power into speed through the transmission ratio of large and small gears.

The manual mill is like a small vertical drilling machine, Yang Wenli stuck the objective lens on the pedestal, and ordered the slave Yang Lishan to desperately shake a steering wheel-like rocking wheel, the abrasive rotated at high speed, he pulled off the abrasive and began to polish, while dripping a cooling liquid made of oil-water mixture.

The abrasive is wrapped with fish glue and quartz sand cloth, which is the ancient version of the abrasive cloth, which is just a kind of abrasive cloth, and there are five different materials of abrasive cloth, which should be polished five times, and the whole grinding process is very cumbersome, compared to the iron rod grinding into a needle, and there is too much, fortunately, it is already a convex lens, a frosted glass embryo in the shape of a prism, and the grinding process is relatively fast.

It is very simple to measure whether a polished convex lens is qualified, look at the focus of the sun, the finer the focus, the higher the brightness, the better, and vice versa.

The polishing of another prism is not simple, the steps are the same, but the measurement method is different, it is to use the darkroom beam measurement method, the thin beam of the darkroom is an absolute straight line, and the prism is refracted light, and the horizontal beam of the prism, if there is an uneven side, the prism will refract the light, proving where to polish, otherwise it proves that the prism is qualified.

Also, the straight side of the prism should be silver-plated, of course, not the modern chemical silver plating, but the use of mercury, that is, mercury, as early as the Qin Dynasty, the mausoleum of Qin Shi Huang used a lot of mercury, and the ancient alchemists used mercury.

Cover the glass with tin paper and drip mercury to obtain an excellent reflective substance, which is also the silver plating method of early mirrors, and after plating, a layer of paint is applied to protect the silver plating layer.

Yang Wenli used these methods to become the first mirror maker in Chinese history, fortunately he used a telescope in his previous life, so he knew the construction principle of the telescope, otherwise he could only make a simple monocular.

The last step is to assemble the telescope, because it is binocular, it is also very troublesome, and you also have to adjust the focus.

Melt with copper, calendered into copper plate, make a frame, copper is soft, easy to make the shape you want, due to the limited time, there is no beauty, not to do any fancy decoration, everything is practical first.

In this way, Yang Wenli took a few slave soldiers, went through hardships, and finally made the world's first binoculars.

…… To be continued