The best photosensitive material is silver bromide. Preparation of silver bromide. Sodium bromide is much more common than potassium bromide. Silver bromide is prepared by the reaction of sodium bromide and silver nitrate. It all had to be done in the darkroom. But Shang Wen covered it with a large blanket. Then he took a lampshade made of red paper and put it on the kerosene lamp. Because of the kerosene lamp. Shang Wen had to come out for a breath. Or build it up with a stand.

Silver bromide is available. Photographic gelatin is barely available. Because gelatin requires fresh beef bones to go through 90 to 100 days to be made. But things have come to this point, and they can only be used reluctantly.

The next step is to make a camera. Make a portable wooden box camera according to the soil method. Shangwen needs to make two. One framing, one photographing. The shutter also uses a mechanical shutter.

Follow Shangwen's immediately. The camera must also have a focal length. For measuring. Shang Wen put a lot of thought into it. With the help of triangulation. Calculate the distance of the third point based on the distance between two known points. This method has been widely used in artillery and architecture. And on this basis, some people began to give birth to geometry. A lot of people are researching. Because the scope involved is very wide. That's what Shang Wen did. He calculates the appropriate distance according to triangulation. Later cameras were equipped with this range-measuring device.

There are also rotatable mirrors. The camera is made entirely of two wooden boxes. This will allow you to adjust the focal length.

Shang Wen made a dual-lens reflex camera. This time it spanned the history of the camera several times. But Shangwen is still satisfied. There is also a flash. The early flashes were all magnesium lights. Shang Wen made an umbrella out of tin foil. Then electrolyze magnesium.

Magnesium was already known in the laboratories of the Qin State. It is mainly prepared by electrolytic lime. The dotting method also prepared active metals such as sodium and potassium. This made the chemical process of the Qin State once again advanced before. These are all the credit of Bai Ai. Ongoing R&D experiments based on a booklet of limited knowledge.

The use of electrolysis also found a poison gas. Chlorine. At the same time, another acid hydrochloric acid is obtained. This is all made in electrolyzed saline. As for efficacy. Laboratory personnel are still working on it.

Chemistry is becoming more and more recognized. Some arsenals began to link chemistry and weapons manufacturing specifically. It was mainly used as a musket propellant. But progress has been very slow. Shang Wen remembers that a gunpowder maker discovered smokeless gunpowder, but because the fiber material used was catkins. Catkins are currently the best fiber material that Qin has found. It is used in many places. For example, papermaking. Banknotes, checks need a lot of catkins to make high-end paper. This pushes up the price of catkins. Use catkins as smokeless gunpowder propellants. It seems a bit extravagant. For this reason. This made the Qin State deviate in the propellant. They turned to other alternative propellants. Because of the relationship between smokeless gunpowder. Machine gun. and other types of ammunition are progressing slowly.

But if there is a loss, there will be a gain. The developers invented another propellant. Picric acid. However, he mainly used it on artillery shells. This led to the beginning of a large-scale advance in artillery technology in the Qin state. Some began to make reloadable guns based on pressure cookers. Metal medicine barrels were also used for medicine packets. The appearance of the detonator. Let an expensive single-base charge shell appear. But there was a problem with the barrel. Because artillery still uses bronze or copper as the launch tube. The demand for steel is being raised again. There is a desperate need for steel.

Steel needs to be forged repeatedly to come out. This has led some people to look for new ways to make steel. This time, though, it's up to chemistry. This is because chemistry uses a series of chemicals to measure its composition. And to lay a good foundation for the mining of minerals.

Shangwen's camera has done pretty much the same. The rest is photographic paper. Look at the time it's already five o'clock. Shangwen decided to take a break. But Yingyu couldn't sleep with excitement. Because of sunglasses. Lots of sunglasses. She wanted to give it a try.

With this in mind. She turned left and couldn't sleep. Turn right and can't sleep.

"Why hasn't it dawned yet. Oh my sunglasses! Yingyu took the sunglasses and put them on.

"No, I can't. I need to get up. Saying that, Yingyu immediately turned over. The maids she tossed had to keep busy, too. Yingyu was so excited. She kept urging her to hurry up.

When it's almost over. I put on a pair of big brown toad glasses and walked out of the door early.

As soon as I went out. The attendant who saw Yingyu was taken aback.

"Ahh

"What is it called. Haven't you seen Princess Ben wearing sunglasses? Hum! "The Yingyu Project has appeared in a new way. I didn't expect someone to understand. It's just a disappointment.

King Qin got up early, and Zhao Gao followed behind King Qin after serving Queen Qin. There are very few documents approved by King Qin himself. Therefore, the more free time the King of Qin has every day.

"Zhao Gao, is today's newspaper here?" King Qin asked.

"I'll pick up the little ones." Zhao Gao respectfully bent over and prepared to leave. As he prepares to turn, Yingyu suddenly appears wearing sunglasses.

Zhao Gao, who had never seen him dressed like this, was frightened to the ground.

"This ......," Zhao Gao didn't speak.

"Hey, hey. Surprised! It's sunglasses! Yingyu said.

"Get up!" Yingyu said.

"What are you doing with your mask?" King Qin was attracted by Zhao Gao's voice and turned his head to ask.

"Father! This is not a mask. These are sunglasses. Shade the sun. With that, Yingyu stepped forward and took off her sunglasses and handed them to King Qin.

"Oh! Mr. Qin made it for you, right? King Qin asked.

Yingyu nodded in agreement.

King Qin put on his sunglasses and looked at it as he spoke.

"Hey! How dark is it this day. Isn't it impossible to see when you wear this? King Qin asked strangely.

"It needs to be used after the sun comes out. Wait for the sun to come out. You don't have to dazzle. Yingyu explained.

"Hmm." King Qin was eager to give it a try. But the sun hadn't risen yet in the morning. Sunglasses are of little use.

"Tell me, what else has Mr. Qin invented?" King Qin took off his sunglasses and asked.

"Father, how do you know that something new is being invented?" Yingyu asked.

"Look at you!" King Qin replied.

"Look at me." Yingyu was puzzled.

"You must have something else to do with you so early. Go ahead! King Qin said.

"Hmm." Yingyu was still puzzled. But my father had to answer first.

"What telegram is he working on. It's all at once that the news can be transmitted. There are also cameras. It's something that can draw my father at once. Yingyu replied truthfully.

"Oh! The widow is going to see it. King Qin said.

"Zhao Gao, prepare the car!" King Qin shouted loudly.