After quelling the cholera incident, because he was surrounded by admiring eyes every day, Downing was actually a little accustomed to the hard life at sea. Finally, Fermat's theorem can be sorted out efficiently.

After more than two months of sea tossing, he finally arrived at the Cape of Good Hope in South Africa, but he did not want to stay on comfortable land for a few more days, because this arduous journey is a big blow, and it will be bad if he is deflated. Sailing is really hard.

Probably the deepest impression of Cape Town was the Constantia wine bar, and he bought a case to drink on board before leaving.

Three days later, the schooner lifted anchor again, and finally, sailed into the Atlantic Ocean, which would be the richest and most important sea for centuries to come, with Great America on the west coast and Greater Europe on the east coast.

In the 19th century Age of Sail, with wooden ships as the core, there was also a terrible shipwreck, fire, unfortunately, the hapless Downing encountered a fire in the vast Atlantic! Fortunately, it was only a small fire, but unfortunately it was the food and fresh water tank that was burning, and because it was a fire in the water storage room, the fire did not spread, otherwise Tang Ning would have to take a lifeboat to escape.

Running out of food? No problem, increase your fishing. Fresh water...... It is possible to boil seawater to make distilled water, but this would cost extra coal, and the drinking water for 630 passengers would not be so easy. As a result, the supply of fresh water was limited, and everyone lived a hard life again.

This hard life is definitely not Tang Ning's turn, he is not only a VIP, but also has a universal molecular separator, pure water manufacturing is too simple. It's just that he can't use the separator to provide enough fresh water to more than 600 passengers, because it will expose his black technology.

Seeing the passengers living a hard life, he was also a little unbearable, thought about it, and finally thought of a trick. Reverse osmosis desalination of seawater. In short, a semi-permeable membrane allows fresh water to pass through but salts such as sodium chloride and ****** cannot pass through, and fresh water can be continuously prepared by applying pressure on one side of the seawater.

So, where to find a semi-permeable membrane on this ship?

This is where the answer comes from the fish. Why can marine fish drink fresh water but humans cannot? That's because marine fish have a "desalination" device, and the epidermal membrane, inner cavity membrane and oral membrane of marine fish are all semi-permeable membranes. When seawater is sucked into the oral cavity, the oral mucosa or the mucosa of the inner cavity blocks the seawater in the oral cavity, and then through inhalation, it increases the pressure of the oral cavity, forming a pressure difference between the inside and outside of the membrane, desalination and absorption of seawater into the body, and the salt and other components that are decomposed and retained in the oral cavity are excreted from the body through the excretory system.

In the digestive system of many types of marine fish, an enzyme (biocatalyst) can be found that makes it possible to peel off the fish film in pieces. So, after a period of exploration, Downing summoned the captain, Rawlinson, and the doctor to observe his process of preparing the semi-permeable membrane, and explained the theory of reverse osmosis desalination while peeling off the membrane.

Some fish are quite large and can tear off considerable membranes, which are hung by seawater and can be harvested by gravity.

This method is fresh! Taste it, it's really fresh water! These nobles really obeyed again. O Master! Now the word has spread throughout the ship, and we have a master of science on board, as if nothing can stop him.

The key to the success or failure of this method is that the biofilm should be washed clean and disinfected with chlorine after peeling off, otherwise there will be bacterial invasion. After three days of trial, the freshwater process was mature, and everyone happily used the enzymes and processes provided by Downing to make semi-permeable membranes. In the end, I got more than 30 pieces of film baggage, so that the special person made fresh water, and the original bitter water shortage life was far away from everyone.

Rawlinson sighed: "I don't know if your welded pure steam steel ship can be built, but your chlorine disinfection method and freshwater generation method should become the standard configuration of sailing ships." When you get to London, build two of these factories as soon as you get there, and I'll invest in them. ”

Tang Ning also sighed: "I really didn't expect the life of the crew to be so difficult, it seems that my shipbuilding plan should be put on the agenda as soon as possible, and the ocean-going giant ship is too important to improve the seafaring life...... By the way, are you familiar with the head of the East India Company's Blake **** shipyard? ”

Rawlinson: "Of course, shipbuilding is so important to our East India Company, how could I not know the people of Blake...... I didn't believe you could build such a fantastic ship, but this time together made me realize that you are a person, you are a person who does what you say! I'm curious, like, would you really do what you said about replacing iron with steel? ”

Downing: "The iron we commonly use now is called wrought iron, such as the one used to lay railroads. It has a very low carbon content of 0. 02% to 0. 08%, so people call it pure iron. It is a metal that has just reached the point of usability in hardness and ductility and has been in use since the Iron Age, beginning in 2000 BC.

At very high temperatures, a drastic change will occur: iron begins to absorb carbon rapidly, and then iron begins to melt, as higher carbon content lowers iron's melting point. The iron thus obtained is called cast iron. It contains 3 to 4 percent. 5% carbon. This high carbon content makes cast iron hard and brittle, shattered under heavy blows, and cannot be forged by blacksmiths at any temperature. However, this cast iron can be used to cast iron utensils that do not require so much toughness, such as iron furnaces, iron pots, cannons, cannon shells, bells, etc.

As you can imagine, the key to turning cast iron back into forging is to use oxygen in the air, which burns off some of the carbon. The present British ironworks do have this craft, which is done by mixing furnaces. As mentioned earlier, when the carbon content is different, the melting point of iron is not the same, and as the carbon content decreases, the cast iron will quickly solidify at a certain temperature point, and this is the best time for molten iron to be burned into iron plates and iron pipes. The very difficult part of this process is that the workers in charge of mixing at this moment have to use very much force to stir the molten iron that is about to solidify, and only the strongest and most skilled mixers can do this kind of work. And such hard work makes the life expectancy of the mixer generally not exceed forty years.

What exactly is steel? At the end of the day, it's a matter of carbon content, and the amount of carbon in steel is at 0. 2% vs. 1. 5% metal, which gives steel a stronger hardness than wrought iron and makes it less brittle than cast iron. Steel is tougher than wrought iron, can get extremely sharp edges, and is more compressive and tensile resistant than cast iron. The current steelmaking method is a process called bonding. It is made by stacking wrought iron with wood charcoal, which is used to increase the carbon content, layer after layer, and heating it in a tightly sealed furnace. This heating process lasts for several days, and then the wrought iron blocks absorb the carbon. In order to make the carbon more evenly distributed, the resulting metal is crushed, recombined with wood toner, and then heated again. The steel obtained in this way is called 'bubble steel'. In order to obtain a homogeneous material, the foam steel needs to be broken and heated repeatedly.

The steel-making process I want to invent is to inject compressed air into the bottom of the furnace full of molten cast iron, so that the carbon content of the cast iron is rapidly reduced, and the most ingenious thing that makes me surpass the stirring furnace is that my oxygen content is controlled by an additive called mirror iron, because the oxygen content in the air is too high, turning the cast iron back into wrought iron, and it is dry in vain, and the mirror iron contains manganese, which will consume a part of the oxygen, so my process is directly steel! And my speed is a few minutes, a few minutes to a few days of the bubble steel method, this is the power of my steel method! ”

Such a long speech, but Rawlinson was not bored at all, he was already deeply intrigued, cowman! Definitely a master! Listening to him clearly, Rawlinson could almost see the revolutionary change that days of steelmaking process could bring about when it was replaced by a few minutes of superb technology. The age of steel is really coming!