Chapter 1093 Leaving Traces
“Oh, yes, is this the lacquer box?”
“Yes.” Zhou Zhi took out a magnifying glass: “The bottom of this box was rebuilt by Qianlong craftsmen. Some of the original traces have been covered up, but not all of them have been covered up.”
“We can only know the original appearance of these traces through scientific means. The first thing that comes to mind is X-ray." While Professor Su was checking the bottom of the box, Zhou Zhi continued to introduce: "But X-ray contains radiation, which will have an irreversible impact on the carbon dating of organic matter. We still think it can be used without it. Try not to use it.”
“I heard that Professor Su has infrared thermal imaging equipment here, so I’m here to bother you.”
"What is the temperature range that this box can withstand?" Professor Su is a very strict person. Thermal imaging must be related to temperature, so Professor Su asked this question.
“Hmm…” What is the temperature range that lacquerware can withstand? Mr. Qi and Zhou Zhi looked at each other, they really didn't know this.
But the general range is still pretty much the same. Zhou Zhi said: "Now in Liangshan Prefecture in the middle of Sichuan, everyone still uses lacquerware to make bowls and plates. They can serve soup and rice without any problem. The high temperature of one hundred degrees can definitely be done. Bear it.”
“Elbow. I’m talking about the Yi people. In fact, there are also Xibe people in the Northeast, who are also experts in making lacquerware.”
Qi Lao added: “The temperature in the Northeast is often tens of degrees below zero. Logically speaking, it’s minus two degrees. Thirty degrees should be no problem.”
"That's easy." Professor Su breathed a sigh of relief: "Then it seems that this cultural relic is quite durable, right?"
"No, no, no, no..." Zhou Zhi was so frightened that he quickly corrected: "It can't be built without resistance." Naizao, we are just talking about a rough range..."
"Well, let's start from minus five degrees and change to forty degrees. Take a look at the overheating imager. "
There is no problem with this temperature. Zhou Zhi still did not forget to remind: "Speed, Professor Su, don't change the temperature too fast..."
Professor Su will The Tixi box was placed in a device similar to a large box, and then the power was turned on, and a rough picture appeared on a screen on the workbench.
"Can you see clearly?" Zhou Zhi asked.
"This is surveillance." Professor Su was good-tempered: "The imaging camera can't see it now."
The assistant quickly adjusted the shooting position so that the three characters on the bottom of the bowl were positioned It could be photographed from the best angle by the infrared camera, and then closed the box: "Professor, let's start adjusting the temperature?"
"Let's start." Professor Su nodded.
The process is very simple. There is a buzzing sound inside the machine, and Zhou Zhi can see the light spots at the bottom of the bowl on the monitoring screen begin to change like clouds receding.
The screen displays from bright to dark. After reaching the initial temperature, turn on the low light, adjust the exposure rate, and then the assistant begins to heat up the environment inside the box. Zhou Zhi feels that the screen in the monitoring room begins to gradually brighten, just like the sunrise.
But the clouds are green.
The assistant tapped the button of the machine a few times at the right time, and the machine made a slight clicking sound. It was probably that the camera was being taken at the right time.
After a while, the box was reopened. The assistant took out the paint box and gave it to Professor Su, and went to develop the film himself.
“Is this lacquer box very valuable?” Professor Su looked at the lacquer box: “Isn’t this the kind of box that ladies in the north use to do sewing on their kangs? I’ve also seen plastic and glass ones. Yes, they’re all pretty.”
In the future, there will be melamine ones, which will look more like this! Zhou Zhi could only complain silently in his heart.
"At least it is an object from before the Qianlong Dynasty." Mr. Qi was equally unimpressed: "If the handwriting on it can be deciphered and it is as we expected, it will be very precious. ""Which words are you guessing? "
"Zhang Chengzao, Zhang Fei's Zhang, achievements are made, and manufacturing is made. Zhou Zhi said: "Zhang Cheng is a master of red and rhinoceros lacquerware in the Yuan Dynasty. If these three characters can match Zhang Cheng's handwriting on the Forbidden City collection, this box should be from the Yuan Dynasty."
"Lacquerware from the Yuan Dynasty? How can it be so well preserved?" Professor Su was a little surprised: "This really looks similar to the things on the bed of the Northeast aunt."
"This is the characteristic of lacquerware. After forming a complex with water molecules, it can stay as good as new for a thousand years." Mr. Qi said: "Don't talk about the Yuan Dynasty, even the ones unearthed from Chu tombs in the Spring and Autumn and Warring States periods All kinds of lacquerware are still well preserved. "
"The most exaggerated piece is the red lacquer wooden bowl from the Hemudu site in 6500 BC." Zhou Zhi said: "Potery, linen, silk, and lacquer are the earliest crafts in our country. Silk and lacquer are still unique to Chinese civilization. After the rise of porcelain, the large-scale use of lacquerware was gradually replaced. "Comrades in materials science can also dig into it. The anti-corrosion performance and adhesion performance are extraordinary."
At this time Professor Su Professor Su’s assistant brought over a few negatives. The negatives were quite special and were as big as a six-page paper. Professor Su placed the negatives on the white frosted glass workbench and turned on the switch. The entire tabletop emitted a soft white light, allowing the contents on the negatives to appear. can be clearly seen.
Seeing the strange expressions on the faces of Mr. Qi and Zhou Zhi, Professor Su also specially explained: "It is said that this table was invented by a child in Sichuan. Children nowadays are so smart. How do you think they figured this out? ”
Mr. Qi laughed loudly and pointed at Zhou Zhi: "You have to ask him about this!"
"What do you mean?" Professor Su didn't understand.
"Hahahaha...because this smart kid you mentioned is sitting in front of you now."
"Huh? Did you invent this table?" Professor Su also laughed: " Isn’t this a coincidence?”
“This was originally used to restore calligraphy and paintings by the elders of the family. Later, it seemed to be useful, so I ordered a batch of them for the school’s Ancient Book Restoration Research Institute. Unexpectedly, they were all passed on. Here it comes..."
After Zhou Zhi finished speaking, he was about to stand up and look at the brand: "Let me see if the manufacturer has authorized it..."
"Sit down!" Mr. Qi quickly reprimanded. It depends on whether it is a three-no product or not for everyone. Embarrassed: “Business matters!”
Infrared thermal imaging has a halo effect, and of course it cannot be as clear as X-rays.
However, infrared thermal imaging also has an additional benefit, which is that it can capture the temperature difference changes of various parts in the temperature zone and reflect it through the depth of the color.
Nowadays, it is still black and white film, and the temperature difference is expressed as a change in gray scale.
In the normal temperature zone of ten degrees and thirty degrees, Professor Su adjusted the temperature change curve very quickly. In the film taken in this temperature zone, the temperature difference between the writing and the carcass is the largest, and the displayed text is also the clearest.
Of course, the specific optical technology is not clear, but at least on the three negatives, three characters can be seen clearly, which is indeed "Zhang Chengzao".
“I missed it again!” Mr. Qi patted Zhou Zhi on the shoulder hard: “Okay, I wouldn’t have noticed it.”
“That’s your old eyesight problem. "It's not a matter of eyesight," Zhou Zhi said modestly. : "I just thought that according to the level of painters made in Qianlong, there would be no traces, so I was more curious."
"Qi Lao, why do you think later painters had to leave some marks? Where are the traces for our descendants?”
(End of this chapter)