The four-wheeled carriage on the first drawing is very beautiful, and with his strict and strong drawing, he only has a few brushstrokes, and a magnificent and beautiful four-wheeled carriage jumps on the paper.

The spacious and bright carriage, the door of the carriage like an open door, and the carriage ladder that is convenient for passengers to get on and off, and the two horse lamps on the left and right sides of the driver's position in front of the carriage, as well as the luggage rack on the top and back of the carriage, are all on the paper, which makes people excited at first sight.

Not to mention anything else, because of the unique characteristics of the four-wheeled carriage, the carriage of the carriage is as spacious as a house, compared to such a four-wheeled carriage, all the two-wheeled carriages of the entire Han Empire, even the "luxury car" given to him by the shopkeeper You when Yan Liqiang returned to Ganzhou from the imperial capital city before, are instantly extremely simple, it is no exaggeration to say that the comparison between the two-wheeled carriage and the four-wheeled carriage is simply the comparison between a motorcycle and a Maybach.

Qian Su's mouth opened wide in shock, and after looking at the first picture a few times, he looked at the second picture below.

In the second picture is the structure of the four-wheeled carriage, on both sides of the carriage, there are bright windows, and in the carriage of the carriage, there are two seats that are as spacious as sofas directly facing each other, which looks extremely comfortable, even if Qian Su has never sat in such a carriage, he just glanced at it, and he was attracted by such a design.

All two-wheeled carriages, because of the limitation of carriage space, it is impossible to move such a comfortable seat to that narrow and cramped space, the entire two-wheeled carriage of the Han Empire is a small bench or a wooden board fixed in the car, the so-called luxury, at most only on the bench and the wooden board on a little fur, some women's special carriage carriage, in order to be comfortable, then directly get a soft collapse that can lie down and sit cross-legged, to be comfortable, naturally not as good as Yan Liqiang painted on the paper of this painting.

"It's ...... Four-wheeled carriage?" Qian Su looked at the two drawings, and then at Yan Liqiang, a look of surprise flashed in his eyes.

"Yes!" Yan Liqiang said with a smile, "Isn't it obvious at a glance?"

Qian Su smiled bitterly, "I have to say, Liqiang, you really draw well, but this four-wheeled carriage is not good at all, if the four-wheeled carriage can be made so simply, I am afraid that all the four-wheeled carriages running in this world will be four-wheeled carriages!"

Yan Liqiang asked knowingly, pretending to be curious, "Oh, I don't know why this four-wheeled carriage is not easy to make?"

"It's actually very simple to make it, but the practicality of this four-wheeled carriage is not strong, why is it not strong, it is because the four wheels of this four-wheeled carriage are fixed on the body, and once you walk, you can't turn at all!" Qian Su pointed to the four wheels of the four-wheeled carriage drawn by Yan Liqiang and said, " So now all the people who pass all over the world are two-wheeled carriages, because two-wheeled carriages can easily turn on the road, and a coachman can control them, and four-wheeled carriages I heard are available in the imperial capital, which is the emperor's throne, but the emperor will only sit on a very small number of times, and he can only walk on a straight official road, and a lot of people have to turn around or something, untie the horses, and lift the carriage, which is too troublesome......

"What if I could solve the steering problem of the four-wheeled carriage?"

"Ah, how can it be ......" Qian Su said habitually without thinking about it......

Yan Liqiang smiled and handed over the third sketch he had drawn to Qian Su, on which he drew the structural diagram of the bogie connected to the front and rear wheels at the bottom of the four-wheeled carriage.

As soon as he saw the picture that Yan Liqiang had brought over, Qian Su's eyes widened instantly, and within a few seconds, his hand holding the picture trembled slightly with excitement.

Seeing Qian Su's appearance, Yan Liqiang sighed, the principle of the four-wheeled carriage is actually not complicated, it is just a layer of window paper, as long as it is pierced, everyone can understand it at a glance. Qian Su said before that the four-wheeled carriage can not be turned, that is because everyone is accustomed to installing four wheels on the same fixed frame, so it is very difficult to make such a four-wheeled car to turn, and the practicality is not high. There are four-wheeled vehicles in it, but the kind of four-wheeled vehicles are heavy-duty vehicles pulled by oxen, and all the turns are completed by pulling the cars with strength by a few oxen pulling the carts in front, and such four-wheeled ox carts have been used even in the rural areas of the country before liberation.

And to solve the steering problem of the four-wheeled carriage, it is very simple, as long as you break through the limitations and inertia of thinking, install the front and rear wheels on two different frames, and then the two frames are connected together with an erected hard shaft, so that the problem of four-wheel steering can be easily solved, which is the bogie of the carriage.

Yan Liqiang had thought about making a four-wheeled carriage before, but at that time, the conditions were not ripe, and it was of little significance to make it, so he didn't do it, and this time on the way back to Ganzhou, Yan Liqiang bumped tens of thousands of miles in the two-wheeled carriage, and he finally learned from the pain and decided to get the four-wheeled carriage out for the benefit of the people of the world.

As the creator of the four-wheeled carriage, even if he can't monopolize all the four-wheeled carriages, but with his fame, as long as he occupies the highest-end part of the four-wheeled carriages, then there will be a steady stream of profits and money rolling towards him, and at the same time, he can also use this to cultivate his own power.

In addition, one of the biggest advantages of the four-wheeled carriage compared with the ordinary two-wheeled carriage is that the carrying capacity is strong, which can greatly improve the carrying capacity of the carriage, which is of little significance to a person, but for a country like the Han Empire, which mainly relies on land to complete the circulation of goods, this has extraordinary significance- The convenience and efficiency of land transportation of goods, first of all, will reduce the logistics and transportation costs of goods, and is conducive to the circulation and migration of goods and people in a wide range, so that commerce can be greatly developed, the development of commerce, the handicraft industry will also develop and flourish, and the improvement of production technology will also have demand and power, which will bring a series of changes......

Of course, if you want to make a high-end four-wheeled carriage, it is not enough to have a carriage bogie, which others will know how to get at a glance.

Therefore, Yan Liqiang then handed Qian Su a picture, on which Yan Liqiang designed a coil spring for shock absorption at the bottom of the carriage and the rear axle......

"This ...... What is this circle?" Qian Su looked at the picture and asked in astonishment.

"This thing, it's called a spring!"

"Spring ......" Qian Su repeated, obviously still a little confused about what a spring is, "What is the use of this thing?"

"It can be soft and hard, big and small, stretch and contract......" After saying this, seeing Qian Su's face became strange, Yan Liqiang reacted suddenly, "Ahem, Uncle Qian, don't think crooked, this thing is used to absorb the shock of the carriage during driving and increase the comfort of the carriage, you will know when it is made!"

Qian Su laughed, "Do you know how to make this thing?"

"Of course!" Yan Liqiang looked at Qian Su seriously, with a look of memory on his face, "I had another dream a few days ago, and in that dream, the fairy old man who once taught me how to save people taught me how to make springs!"

In an era when there is no spring, the spring is definitely a "high-tech" product, and because of its special production process, Yan Liqiang can completely control the production process of the spring in his own hands, so that others can see it in a short time but can not make it, so that they can open the gap between the four-wheeled carriage they produce and the four-wheeled carriage produced by others, and lay the status of the "luxury car" produced by the Ganzhou Manufacturing Bureau in this era......

The Rolls-Royce in Yan's four-wheeled carriage is not a dream......

Qian Su suddenly looked at Yan Liqiang eagerly, "Liqiang, I beg you something?"

"What's the matter, Uncle Qian?"

"Can you tell that fairy grandfather, in my dream, I also welcome him at any time, really, I am very Taoist, since I was a child, I want to find such a master to learn skills, let him also teach me a few tricks!"