Wizard: I brought the wrong system

After cooling in the stone grooves, the next step is sanding.

First rub back and forth with the same grooved grindstone. The hardness of quartz glass is higher than that of ordinary glass, but it cannot withstand Yarrow's strength. With the constant friction back and forth, the surface of the glass is gradually blurred and gray. But the degree of convex mirror is getting more and more accurate.

After polishing the large convex mirror, and then polishing the small one, the two convex mirrors became dusty, and some small scratches could be vaguely seen on them.

Yarrow changed the material and continued to polish.

Fine grinding sheets, fine sand, semolina, pearl powder... Yarrow has no sandpaper to use, so he can only find these natural materials instead.

The fine sand is about [-] mesh, the coarse flour is about [-] mesh, and the pearl powder has reached [-] mesh... Yarrow's movements gradually become irritable.

The mesh number originally refers to the fineness of the sandpaper, specifically the number of particles per square centimeter. The higher the mesh number, the more obvious the polishing effect will be.

As long as you have patience and enough grinding materials, a stone can be polished into a shining mirror.

When grinding, the number of meshes can only be increased from small to large, and there should not even be too many numbers in the middle, otherwise it will be very laborious to polish.

Just like Yugong Yishan, what he took was a small spoon.

After grinding the one-digit mesh, use the thousand-digit and ten-thousand-digit mesh. The tooth grooves left in the front are too deep, and the sanding of the thousand- and ten-thousand-digit mesh can only be ground to the surface of the tip of the tooth groove, and it will be very difficult to polish. strenuous.

Of course, [-] mesh is still not enough, Yarrow continued to change materials.

Linen can be polished to more than 1000 meshes, and it will feel "moist" after polishing.

Human hands or wearing cotton gloves can reach [-] eyes. At this time, the lens is like some objects that have been used for a long time. It can illuminate the figure but it is difficult to see the appearance.

The last is wool felt, and the finished product can reach the level of [-] to [-] meshes.

In the last polishing process of glass products in the previous life, wool felt was used, and this step is almost ready.

"Finally done!"

Yarrow shook his sore arm, looked at the two transparent lenses, and finally breathed a sigh of relief.

Pick up the mirror barrel made earlier, install the two lenses, and try to look at it.

"Huh? Why is it a bit blurry?"

It's definitely not a lens issue.

After all, Yarrow had already checked the transparency of a single lens.

"Is the data given by the academy wrong?"

Yarrow tried to close the mirror barrel, but the more the mirror barrel was closed, the more blurred the vision became.

This shows that the light intersection distance of the two lenses exceeds the length of the mirror barrel.

"Is it because quartz glass has a lower refractive index?"

When the angle of incidence of light is fixed, the greater the refractive index, the smaller the angle of refraction.

From this point of view, it seems that ordinary glass is better. After all, the higher the refractive index, the shorter the distance between the lens barrels.

You should know that the curvature of the lens can be adjusted, as long as the convexity is adjusted, the lens barrel can be as long as you want.

But the higher the refractive index, the more severe the dispersion and the lower the sharpness.

Taking the current lens as an example, if the distance between the middle lens barrels is adjusted properly, the distance you can see will be much farther, and the definition will be higher.

This is a good thing.

It is not too difficult to adjust, just add a section to the mirror barrel.

It’s just that the width of the mirror barrel and the convexity of the lens have been fixed long ago. Even if one section is added, you can only see the farthest distance, unlike the original mirror barrel, which can be divided into three sections for viewing.

If you want to achieve the original effect, you need to recalculate the width and length of the lens without adjusting the lens power.

Or continue to debug and modify based on experience.

Yarrow doesn't remember the refractive index of quartz glass, and it takes a lot of work to calculate, not to mention that in the current situation, as long as the telescope can see far enough, there is no need to worry about adjusting the distance.

After tidying up the small courtyard a little, I picked some materials and daily necessities for the space ring.

Yarrow walked into the forest on foot. After making sure that there was no one around, he activated the flying pendant with his own magic power. After reaching the limit height of the flying pendant, he got into the control panel of the hang glider, controlled the hang glider, and headed towards Perrin Manor. direction to fly.

The Perrin Territory is close to the mountains, and the surrounding terrain is uneven and there are many valleys. Especially on the side close to the Perrin Territory, there are not only deep pits, but also two towering peaks that can be seen from Perrin Castle.

Due to the remoteness of the terrain and the steep roads, neither peak has a name.

Yarrow's goal was the shorter and closer mountain.

Wangshan ran to death, even though Yarrow had looked at the mountain in the castle, but due to the distance, he could not estimate the size of the mountain.

It wasn't until Yarrow made a half-circle and landed on the mountain peak that he saw a few towering 'little trees' in his memory, and looked back at the castle, but he could only see a small black dot. How far is the mountain.

"That's good too. Such a long distance can also prevent the wizards who come after us from finding their hiding place."

Among the tricks exchanged by Yarrow, there is a wind spell that can allow people's eyes to see far away. The original name is just a word, which cannot be directly translated. Yarrow called it 'Eagle Eye' for comparison.

In fact, not only the wind system, but also many spells that can see far away in other systems, but Yarrow made a choice and exchanged all the contribution points without wasting.

"The exchange price of far-sighted tricks is not high, which may also mean that this kind of spells have a high circulation rate, and it is still not safe enough to just hide so far."

Thinking of this, Arrow climbed up the tree, jumped towards the edge of the mountain, and stopped on the side of the castle.

"It should be almost here."

This is the sunny side of the mountain, and the location chosen by Yarrow is a corner of a rock. As long as you get out of the cover of the rock, you can see the castle in a glance.

Setting up the binoculars in the corner of the rock, Yarrow tried to see the castle.

"The quartz telescope is really good. Although I still can't see everyone's appearance clearly, I can already vaguely see everyone's clothes. Based on these clothes, I can roughly tell who is who."

After confirming that the telescope was indeed effective, Yarrow took some dry grass and vines from the ground, weaved it into a fine net, and then covered the lens of the telescope to prevent the telescope from reflecting light and being noticed by others.

After finishing these, Yarrow began to organize his living.

He didn't intend to make it too complicated, so he directly covered the hang glider in the cracks between the rocks, and then pressed the edge of the hang glider with stones.

Then I cleaned the ground, dug a trench to divert rainwater, and spread a layer of sulfur powder on the ground to get rid of mosquitoes.

After finishing these, he took out all the grease accumulated in the castle in the past few months from the space ring.