Several old gentlemen crowded in front of the window, watching Ma Du lead a group of students with their cheeks puffed up and their heads up to spray water into the sky, all of them were stunned. Zhu Sheng stroked his beard and said with doubts on his face: "This ...... Is this the science of things in Hawaii? He transferred classes for half a day, just to take the students to spray water on the playground? ”

Song Kedao: "This is simply nonsense, Mr. Yunsheng is not annoyed, I am just scolding him!" ”

Zhu Sheng grabbed him, "Kewen is not in a hurry, Xuanzhong is not a person who does not know the severity, you see that those students are nodding frequently, obviously not messing around." The old man just couldn't understand it, and I asked myself to know some astrological divination and feng shui miscellaneous science, but I really don't know which school he belongs to. Have you ever seen it? Who knew that several learned old gentlemen shook their heads in unison.

Madu screwed the lid on the kettle and said to the students with wet chests: "Now you understand, the white sunlight you usually see is actually made of a mixture of colors!" ”

"Got it!"

Chang Sheng touched his head, "When I was a child, I often sprayed water with Chang Sen and played, and I have seen it after the rainbow rain, but I have never thought about it, or Mr. is amazing!" ”

"No matter how good the sycophants are, there is no time for the exam, now follow me back to the classroom, let's talk about the spread of light!" When Madu closed the classroom doors and windows and explained the principle of small hole imaging to the students, he didn't know that a few old guys were lewdly poking through the window paper to peek at him lecturing.

After looking at it for a while, Zhu Sheng retracted his head, let out a long breath, and his face showed a point of joy, "Xuanzhong is mysterious, the old man is always worried about what kind of crooked and evil knowledge this Hawaiian knowledge is, and now he is finally relieved." ”

Tao An smiled and asked, "Mr. Yunsheng is afraid that he has seen the doorway, so he might as well talk to us!" ”

"Huh...... It turns out that this Hawaii is the knowledge of the Mo family. ”

Song Ke said with a relaxed look on his face: "I have long said that Xuanzhong's mastery of the instrument is very likely to be the lineage of the Mo family, and Mr. Yunsheng still doesn't believe it!" ”

"The Mo family that the old man knows is not as capable as him, and he is familiar with the art of Huang, who knows which one he is. But now it's finally certain that the experiment he did just now was mentioned in the "Book of Ink"! Zhu Sheng bowed his hand, "Let's all disperse, take a good rest, and we have classes in the afternoon." ”

Zhu Sheng returned to his office, picked up a blank fold from his desk, wrote only the word "ink" on it, put it together and put it in his sleeve, and handed it to a guard outside the academy.

Watching the guard leave quickly, Zhu Sheng smiled bitterly and said to himself: "This last errand is finally done, and you can easily live in the future, hehe......"

Ma Du put the small vanity mirror together and put it in his arms, and took out the telescope and held it in his hand, "This thing may be the first time you have seen ...... thing."

"I know, that's my father's clairvoyant mirror, you can see thousands of miles from afar!"

"You talk a lot!" Ma Du glared at Zhu Xiaoer, and then said to the students: "I called him a telescope for this thing, it can indeed see far, Zhu Fan said that he can see thousands of miles from afar, and this statement is not accurate, it just magnifies the tiny objects that look at us from a distance." Come here and feel them one by one! ”

Madu took the telescope and asked all the students in the class to come over and stand at the door of the classroom to feel the telescope. The students who had seen it shouted amazingly, and the students who were still queuing up were full of anticipation, and when everyone watched them one by one, Ma Du said, "What do you think?" ”

Chang Sheng got up and said: "It is indeed a good baby, I heard my father say that in addition to the emperor, this telescope was only used by Wei Guogong when he went on the expedition, which made my father envious." ”

Fu Youde's son Fu Zhong said: "My father has seen it once, and he is also very greedy, he said that this telescope is the only artifact for watching the enemy on the battlefield!" ”

"My dad also likes this telescope, but it's a pity that there is only one such treasure!"

……

The children of the noble family expressed their father's desire for telescopes.

Ma Du smiled and asked, "Is it only your Lao Tzu who likes it, don't you like it?" As long as you are willing to work hard, not only your battle array can kill the enemy, but you can also have it! ”

"Really!" The classroom of all the students immediately burst into jubilation.

"With this, you can peek at the girl of Qinhuai River taking a bath!" I don't know who shouted, so that Ma Du Dasheng felt like a confidant, it seems that no matter ancient or modern, telescopes can arouse the most filthy thoughts in men's hearts.

But at this time, some people like to pour cold water, Zhu Xiaoer said coldly: "Uncle, don't lie anymore, as far as I know, you only have this one telescope, and you are dedicated to my father." The students couldn't help but show disappointment when they heard this.

Ma Du said: "It's true that there is only one telescope, but can't you do it again?" ”

Zhu Xiaoer was the first to be calm and took the case, "Uncle will do it?" Make one for me, and I'll never mess with you again. The other students also gathered around, their eyes full of eagerness!

"I haven't done it, I just know the truth!" Ma Du smiled: "You have hands and feet, why let me do it!" ”

Zhu Xiaoer sat back on the chair, "Uncle is really good at deceiving people!" ”

The other students were also discouraged, and Chang Sheng said: "Sir, don't be joking, I can make such an artifact with the hands of mortals!" ”

"You underestimate yourself too much, and you look too high at this telescope, it's not as complicated as you think." With a few clicks, Madu removed the two lenses on one of the tubes.

Seeing this, Zhu Xiaoer exclaimed loudly, "Uncle, you destroyed things, see how you explain to your father!" ”

"What are you yelling about! I can't pretend to go back! Zhu Rong, come and take a look, this thing is definitely not as complicated as you think, do you see it, it's just two glass pieces, plus an empty tube! ”

Zhu Xiaoer came over and took a closer look, and asked incredulously: "Is there really only these?" It's that simple! ”

"That's right, it's as simple as that, you don't have to tear off the other half. It's just that these two glass lenses are different from your common ones, one is called a concave lens, which is thick around and thin in the middle, which has the effect of diverging light, and the other is a convex lens and a concave lens, which are thin on both sides and thick in the middle, which can gather light......"

When Madu took the convex lens and ignited a pinch of scraps of paper, the students couldn't help but let out an exclamation, Madu pointed to the light spot on the ground, and said: "Moving the lens to form the smallest light spot, the distance between the lens and the light spot is the focal length, if you want to make a telescope, you have to measure this parameter......

As long as you know the principle and have the right materials, it is not difficult to make a few telescopes, of course, the garbage produced by the glass workshop cannot make lenses. There is also such a thing as crystal, which has been used as a substitute until China has no capacity to produce optical glass.

In Haizhou Qu County (Lianyungang Donghai County) is rich in this thing, the price of cabbage in later generations is almost the same, the kind of crystal trophy with good texture is only a few dozen yuan of cost. However, it has not yet been developed, and Madu has long had a variety of rough stones mined by craftsmen who know the goods.

The students did not disappoint Ma Du, but in twenty days, they came up with several magnification monoculars, and even came up with a set of production technology that was quite dodging.

Lao Zhu took the monocular off his eyes and asked incredulously, "Second child, did you make this?" Although this telescope was not as good as the one that Madu had offered, it was far beyond his expectations.

Zhu Xiaoer nodded, "Back to my father, it was produced by the child's organization!" Of course, there is also the help of classmates, as well as those craftsmen who polish the lenses! "It doesn't seem like there's anything wrong with Mado.

Zhu Xiaoer said and took out a booklet again, "There is also a method for making a telescope here, dedicated to my father!" ”