In less than half a day's work, the goldsmith took the two finished telescope barrels. The goldsmith opened the barrel first, and the two cylinders were divided into four halves of the cylinder wall.

According to the position on the diagram I drew, I don't know what tool was used to chisel a neat and shallow groove on the inner wall of the semi-cylinder, and the groove was just right for the edge of the wafer to get stuck in.

"When the envoy installs all these chips, take the small ones back and wrap them with gold wires, and it's done." The goldsmith said respectfully.

Zhou Nan noticed that at one end of the barrel of a telescope, there are four raised ridges, and at one end of the other barrel, there are four grooves, which are in line with the position of the joint of the cylinder body on the drawing he draw.

Zhou Nan tried to insert one ridge into the groove of the other section, and only the rib and groove the thickness of a grain of rice matched seamlessly.

Zhou Nan tried to push back and forth, and the two barrels slid straight inside, which was very dexterous.

"Good!" Zhou Nan said with satisfaction,

"It's just that how do you get this tube plugged in and never pulled out again?"

"It's easy, too. The small one can be filled with the inner wall at the end of the groove, and when the raised edge slides here, it will stumble on the filled place, and it will not come out naturally. Zhou Nan saw that the goldsmith had a way, so he deliberately took the box containing the crystal lens in front of him, separated the barrels of the two telescopes, and then selected the crystal wafers of the appropriate size and thickness from the box according to the grooves made on the inside of the barrel, placed them in front of the barrel one by one, and pretended to be stuck on the groove, and then said to the goldsmith who was watching from the sidelines: "Go back, and when I have finished installing it, let people call you." The craftsman went out with his head down.

Only then did Zhou Nan take out the unused wafers, and only chose a large and thin convex lens, and a slightly smaller thin concave lens.

In the past few days, Zhou Nan has already tested with wafers of different sizes and thicknesses, and thin wafers can be seen as big, but thick ones are not as good as thin ones.

In terms of size, it is natural that the magnification of large wafers is greater. According to the effect, the two that Zhou Nan took just now can only be relatively good, and the best pair of chips, Zhou Nan naturally wants to keep them for himself.

Zhou Nan put the two chips into two cylinders respectively, and then inserted the two cylinders together, and then took the combined telescope to look out, the nearby leaves did not look, Zhou Nan looked around, looked out from the courtyard of the post house, and could only see the corner tower on the wall of the palace in the distance, and the inner city wall in the south.

Zhou Nan first looked at the corner tower, tried to push and pull the sliding barrel body back and forth, and gradually, a wooden window appeared in front of him, the vermilion lacquer window lattice, and the gray green bricks were clearly visible.

Zhou Nan moved up and down slightly, and saw a guard of the forbidden army standing next to the pillar of the corner tower, but he couldn't see his face clearly.

Zhou Nan is already very satisfied with this effect, and now it is determined that as long as the barrel of the telescope is added to the outside, a monocular telescope will be made.

Zhou Nan didn't let Xiao Jiu call the craftsman, but took out the chip inside first, and went to the goldsmith with the two barrels, and asked the goldsmith to fill in the grooves in the barrel as he just said, and make the upper stopper.

When it is done, he inserts the crystal wafer himself, closes the barrel of the telescope, and finally asks the craftsman to seal the barrel.

The goldsmith was busy fixing the grooved barrel to the worktop, holding a small hammer and chisel at the end of the groove

"Jingle Bell" was tinkered with for a while, and finally polished it with a file until the goldsmith himself was satisfied, and then handed it to Zhou Nan.

Zhou Nan took these two cylinders, returned to his room, and asked Xiao Jiu'er to go to Shen Ding to ask for some boiled glue.

Zhou Nan thought about filling the groove of the card crystal wafer with glue, so that the wafer could be fixed, and secondly, it would also play the role of a filler to protect the wafer from shock and impact.

After a while, Xiao Jiu'er came over with a porcelain bowl containing some hot glue. The glue boiled by people in this era is made of horns, tendons, and even fish maws, and the taste is not very good.

Zhou Nan took out the thin wood chips he had prepared, dipped them in some glue, and wiped them down the groove.

The groove of the chip is very narrow, and the chip is already very suitable after the chip is stuck in, and these glues only play a fixed and buffering role.

So Zhou Nan only painted very little, and after the front and rear grooves were painted, Zhou Nan put the two selected crystal chips into it.

Then take advantage of the fact that the barrel body has not been closed, put the end of the barrel body with convex ridges, align it with the groove, and finally buckle the cylinder body with grooves.

Zhou Nan took the mounted telescope and came to the goldsmith, and asked the goldsmith to seal the two cylinders, and said that if it could not be sealed properly, it would enter the dust, and the treasure would be wasted.

The goldsmith listened to what Zhou Nan said, and he didn't need gold thread to wrap it, so he simply turned a furnace of gold water, except for the parts that needed to be sliding, and the rest of the places were poured with gold water.

In this way, you want to open the telescope unless you melt it down or smash it open.

"Tomorrow I will dedicate this treasure to His Majesty the Emperor, and the outside will naturally be decorated. How to decorate the utensils in the palace, you just do it as usual. Zhou Nan said to the goldsmith, and he turned and left.

The first test product was naturally given to Zhao Ji, and he couldn't use someone else's crystal in vain.

Of the sixteen crystal pieces, only two were used, and of course he wanted to make another pair for his own use, and Zhou Nan also had to bring back the remaining crystal chips and let his craftsmen build telescopes.

Next, Zhou Nan is to give the telescope to Zhao Ji through the embassy envoys Cai You and Li Bangyan.

The telescope was given to Zhao Ji, and Zhao Ji was reluctant to give it to the generals of the front line, at most, he cherished it and put it away in a box.

If it was replaced with a hot air balloon, Zhou Nan would not give it to Zhao Ji - Da Song also has firearms such as thunder, although the explosion power is small, but if it is combined with a hot air balloon and flies to his head, even arson with poisonous smoke, isn't that causing trouble for himself?

I gave Zhao Ji such a treasure that can look far away, but I just hope that Zhao Ji will be happy and can smoothly agree to open the border market with each other.

Thinking of this, Zhou Nan asked Xiao Jiu'er to find Yi Cheng, and asked Yi Cheng to find these two pavilion companions, and said that there was something important to discuss, and invited the two to meet at the post house.