Wizard: I brought the wrong system.

Chapter 334 Polishing
After the stone has cooled in the grooves, the next step is polishing.

First, use a whetstone with the same groove to rub back and forth. Quartz glass is harder than ordinary glass, but it can't withstand Yaro's strength. With continuous back and forth rubbing, the surface of the glass gradually becomes blurry and gray, but the power of the convex lens becomes more and more accurate.

After polishing the large convex lens, the smaller one was polished, and both lenses became grayish, with some tiny scratches faintly visible on them.

Yaro changed the materials and continued polishing.

Fine grinding discs, fine sand, coarse flour, pearl powder... Yaro couldn't use sandpaper, so he had to find these natural materials to substitute.

The fine sand is around forty mesh, the coarse flour is around eighty mesh, and the pearl powder is already two hundred mesh... Yaro's actions gradually became more irritable.

The term "mesh count" originally refers to the fineness of sandpaper, specifically the number of particles per square centimeter. The higher the mesh count, the more pronounced the gloss effect after polishing.

With enough patience and enough polishing material, even a stone can be polished into a mirror that reflects light.

When sanding, the grit number can only be increased from small to large, and the intervals between them cannot be too large, otherwise sanding will be very difficult.

Like the Foolish Old Man who moved mountains, but he was only using a small soup spoon.

After grinding the units digit, you move on to the thousands and ten-thousands digits. Since the grooves left in the previous digits are too deep, the grit for the thousands and ten-thousands digits can only grind down to the surface of the groove tip, making the grinding process very difficult.

Of course, two hundred pieces were still not enough, so Yaro continued to change the materials.

Linen can be sanded to a grit of over 1,000, and once sanded properly, it will have a smooth, lustrous feel.

A human hand, or one wearing cotton gloves, can have a lens with a resolution of 3,000. At this level, the lens is like an old, worn-out object; it can reflect a person's image but it's difficult to see their features clearly.

Finally, there's wool felt, the finished product of which can reach a mesh size of 5,000 to 7,000.

In the past, the final polishing process for glass products used wool felt, and once this step was completed, it was almost done.

"Finally done!"

Yaro shook his aching arms, looked at the two clear lenses, and finally breathed a sigh of relief.

Pick up the mirror tube you made earlier, put the two lenses in, and try it out.

"Huh? Why is it a bit blurry?"

This is definitely not a problem with the lenses.

After all, Yaro had already checked the transparency of each individual lens.

"Is the data provided by the college incorrect?"

Yaro tried to close the mirror barrel, but the closer he closed it, the blurrier his vision became.

This indicates that the distance between the light rays from the two lenses exceeds the length of the lens 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 perspective alone, it seems that ordinary glass is better, since a higher refractive index means a shorter lens barrel distance is required.

However, it's important to know that the curvature of the lenses can be adjusted. As long as the convexity is adjusted, the lens barrel can be made as long as desired.

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

With current lenses, if the distance between the central lens barrels is adjusted properly, the viewing distance will be much greater, and the clarity will also be higher. This is a good thing.

Adjusting it isn't too difficult; you just need to add a section to the lens barrel.

However, the width of the lens barrel and the convexity of the lens have long been fixed. Even if an additional section is added, it can only see the farthest distance and cannot be divided into three sections like the original lens barrel.

To achieve the original effect without adjusting the lens power, the width and length of the lens need to be recalculated.

Alternatively, one can continuously debug and modify based on experience.

Yarrow couldn't remember the refractive index of the quartz glass, as it would be quite time-consuming to calculate. Moreover, given the current situation, as long as the telescope could see far enough, there was no need to worry about adjusting the distance.

I tidied up the courtyard a bit and selected some materials and daily necessities to store in the space ring.

Yaro walked into the forest, and after confirming that no one was around, he activated the flying pendant with his own magic. Once he reached the maximum altitude of the flying pendant, he climbed into the control panel of the glider and controlled the glider to fly towards the direction of Perrin Manor.

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

Due to their remote location and treacherous roads, neither mountain peak had a name.

Aro's goal was the shorter, closer mountain.

"Looking at a mountain makes a horse run itself to death." Even though Yaro had already surveyed the mountain from inside the castle, he still couldn't estimate its size due to the distance.

When Yaro landed on the mountain peak after circling around a small part of it, and saw a few towering 'small trees' reaching into the clouds, but could only see a small black dot when he looked back at the castle, he realized just how far away the mountain was.

"That's good. At such a distance, we can prevent any tracking wizards from discovering our hiding place."

Among the magic tricks that Yaro exchanged was a wind-based spell that could make people see very far. Its original name was just one word and could not be directly translated, so Yaro referred to it as 'Eagle Eye'.

Actually, it's not just the wind element; other elements also have many spells that allow you to see far away. It's just that Yaro made a choice and didn't waste any contribution points by exchanging them all.

"The exchange rate for magic tricks from a distance is not high, which may indicate that this type of magic is very popular. Simply hiding this far away is still not enough to ensure safety."

With that thought in mind, Yaro climbed the tree, leaped towards the edge of the mountain, and stopped on the side facing the castle.

"This should be about right."

This is the sunny side of the mountain peak, and the spot that Yaro chose is a corner of the rocks. Once you step out of the rocks, you can see the castle in its entirety.

Yaro set up a telescope in a corner of the rocks and tried to get a look at the castle.

"The quartz telescope is indeed quite good. Although it still cannot make out everyone's face clearly, it can make out their clothes. Based on their clothes, it can roughly tell who is who."

After confirming that the telescope was indeed effective, Yaro picked some dry grass vines from the ground, wove them into a fine net, and then covered the telescope lens to prevent it from reflecting light and alerting others to anything unusual.

Having done all that, Yaro began to tidy up his dwelling.

He didn't plan to make it too complicated; he simply covered the hang glider with the crevice between the rocks and then used stones to weigh down the edges of the hang glider.

Then the ground was cleaned up, a ditch was dug to drain rainwater, and a layer of sulfur powder was spread on the ground to repel mosquitoes.

After finishing all that, he took out all the grease that had accumulated in the castle over the past few months from his spatial ring.

(End of this chapter)