As for the serious problem of air leakage of the rear-loading gun, we can only ignore it for the time being, after all, the difficulty of building a rear-loading gun is too great, and the cost is too high, including the barrel processing, shell shell, contact fuse, the robustness of the locking system, and so on, all rely on the workers to manually add machinery to solve the problem, the cost of building a rear-loading gun is equivalent to ten front-loading rifled guns, and the price of shells for rear-loading guns is more than ten times more expensive than that of smoothbore guns. Pen, fun, and www.biquge.info

In fact, the problem of producing after-loading guns is not less than the problem of producing metal shell bullets, but the arrival of Wang Xinyu has distorted the science and technology tree, which has cost a lot of silver to create a few rear-loading guns, and after using it several times, it was found that the ammunition cost of that kind of gun is ridiculously high, and the problem of air leakage in the gun bolt is serious.

Therefore, instead of building expensive rear-loading guns, it is better to build more rockets and new front-loading smoothbore guns, and then build a batch of front-loading rifled guns to make up for the accuracy.

As for the Mini bullet, the difficulty of making the Mini bullet is not much lower than that of the metal shell bullet, and in real history, the Mini bullet is nothing more than a transition, and soon after the birth of the Mini bullet, the metal shell bullet appeared.

However, the technical requirements for creating metal cartridge shells are too high, and the current development trend is to make paper cartridge shells for rear-loading guns, and the key is to solve the problem of air leakage of rear-loading guns.

The Ming fleet sailed in from the mouth of the Yangtze River and arrived at Wusongkou.

Wang Xinyu got off the boat at Wusongkou Wharf, and saw that there was a railway on the wharf extending into the distance, which was the first railway in the south of the Yangtze River, Songhu Railway, with the starting point being Shanghai North Railway Station and ending at Wusongkou. The railway is at Shanghai North Railway Station and is connected to the Beijing-Shanghai railway, which is under construction. However, the Beijing-Shanghai railway is not from Beijing to Shanghai, but from Nanjing to Shanghai. In Shanghai North Railway Station, there is also a Shanghai-Hangzhou railway leading to Hangzhou.

Jiangnan in April, not as hot as Dongfan, the climate is still relatively cold, there is a feeling of wet and cold, even colder than the Central Plains, people come and go on the dock and the street, some people wear long robes and Confucian shirts, some wear thick cloth shorts, and some people wear Western-style copper button clothes, the hairstyles on the top of people's heads are also different, most of them are turbans, and some people cut a short hair, after all, from the Manchu Qing Dynasty's money rattail braids changed not long ago, some people feel that short hair is more comfortable, I just cut my hair short.

There are also some people who have almost bare heads, leaving only a small handful of hair at the back of their heads, which can be tied into a money rattail at any time, and most of those people are businessmen who travel between the north and the south, and if they cut off the hair at the back of their heads, then they will not be able to tie them into braids after returning to the north, and they will be beheaded. But when it comes to Daming, money rattail pigtails are not allowed, so you can only use this nondescript hairstyle. Fortunately, Daming here is not strict about what hairstyle to keep, as long as you don't drag an ugly braid on the back of your head, it doesn't matter, so it is convenient for businessmen who come and go from the south to the north.

"There are a lot of businessmen who come and go, and many of them have a relationship with the officials in the north, and there are even banner people who come to do business. Most of the people who came here were smuggling grain, salt, tobacco and special offerings of the Eight Banners, which were very profitable to send to the north, and the smuggling was too rampant, even the banner people were smuggling, and the Tartar court could not restrain it. Shanghai Governor Yao Tingxuan briefed Wang Xinyu on the situation in the Shanghai market.

Li Guangdi asked: "The Huguang granary is controlled by our army, the transportation has also been cut off, and the northern captives are short of grain, so why don't you restrict the smuggling of grain?" ”

Yao Tingxuan replied: "We have set up a checkpoint along the river, and the grain transported to the north has to be taxed very highly. It is not a solution to completely cut off the food from the north, not only the Tartars in the north, but also the people, if the food is completely cut off, will not the people also starve to death? ”

"Confused!" Li Guangdi shook his head, "This smuggled grain went to the north, and how many ordinary people can afford it?" It's not like it was bought by the Tartars! ”

Wang Xinyu laughed: "Tartars want to use silver to buy food, so let them buy it!" Didn't they plunder in Korea and grab a lot of gold and silver treasures? We sold grain at a high price and swept over their treasures of gold and silver. That way we'll be able to build more guns to fight them again! ”

On the railway line, a small train is parked. Although the Songhu Railway was a standard-gauge railway, it was not possible to build a larger steam engine because of the backward steam locomotive technology, so the trains running on this railway line were not much larger than the trains running on the Dongfan narrow-gauge railway. The locomotive of this train weighed eight tons and the steam engine had a power of seventy horsepower, which was already an improved high-power steam engine. Behind the locomotive was a three-car passenger car, which was less than two meters wide and twelve meters long, which was much smaller than the later standard gauge passenger cars.

"The carriage is too small, not as spacious as the horse-drawn rail car." Wang Xinyu said.

"If the carriage is bigger, the speed is slower. At present, the speed of this car can reach 150 miles in an hour, and if a large carriage is used, the speed is less than 80 miles. Yao Tingxuan replied.

"Woo-" The steam locomotive pulled three carriages and slowly accelerated on the railway line, soon reaching a top speed of thirty-five kilometers per hour. Not to mention that this speed is compared with the later EMUs, even the ordinary express train with a speed of 120 kilometers per hour is far from comparable. But in this era, such a speed is already a gallop. The train is speeding on the Songhu Railway, and the horse-drawn carriages on the road next to it are constantly being overtaken.

The journey from Wusongkou to Shanghai North Railway Station has not yet been fully developed, and apart from the newly built gun factory and steel factory, the north of Shanghai is still a rice field.

As the train approaches Shanghai North Railway Station, the scene is different, with three- and four-storey buildings lining the way, even five- and six-storey high-rise buildings, and even seven- and eight-storey "skyscrapers" are not uncommon. In this era, in fact, it was not too difficult to build a seven-story building, and the Han people had the technology to build a seven-story stone tower, and after having cement, it was not difficult to build a seven-story building. However, no matter how tall the building is, it is very difficult to get from the first floor to the top floor, and before the invention of the elevator, it was not suitable to build a higher building.

It was once suggested that a high-rise building could be built by using a mule-drawn winch to send people to the roof. Later, after the steam engine was introduced, it was proposed to use the steam engine to pull the winch and send people to the roof. However, these methods were all rejected, it was too inconvenient, whether it was a mule or a steam engine, it was difficult to control the elevator to stop on the appropriate floor.

In the future, of course, it will be different after having an electric motor, the motor is easy to control, as long as the button is pressed to start, and then pressed to stop, you can accurately let the elevator reach the floor you need.