To put it bluntly, it is to find the distance from the third point in the distance to this place according to the distance between two known points.

is used, which is the Pythagorean law.

As for the Pythagorean law, it was discussed as early as in "Nine Chapters of Arithmetic", and the children of the family are naturally no strangers to this.

However, due to the lack of suitable instruments, the means of angle measurement are limited and the accuracy is not high.

Historically, in 1730, the British mechanic Sison invented the vernier theodolite, which improved the observation accuracy of angles and simplified the process of measurement and calculation.

The advent of vernier theodolite also provides more accurate data for drawing maps.

When Zhu Cijiong proposed this idea, the craftsmen were simply stunned.

At this time, it was already 1667, and there was no problem at all in making a vernier theodolite.

With Zhu Cijiong's drawings, the vernier theodolite was quickly tinkered with.

Of course, the accuracy is naturally not comparable to that of later generations of optical distance meters.

As for the change in the unit of length......

Although the error of the Ming ruler is almost none, Zhu Cijiong is not used to the conversion of the ternary system, so he changed the unit of length by taking advantage of the trend, changing the minutes, inches, rulers, and zhang to the millimeters, centimeters, decimeters, and meters that were familiar to later generations.

The soldier had already taken a cloth ruler and measured the specific distance.

"Your Highness, between the two is 141.63 meters."

The soldier's words made Ma Sanwa's face red.

They had measured countless times on the flat ground, and the error was almost the same, but they didn't expect that there would still be a mistake on the hillside.

"Your Highness, we ...... We ......"

Ma Sanwa's face was flushed, His Royal Highness gave him so much trust!

At the end of last year, he was given a red envelope of ten taels of silver, and even the craftsmen had their own rewards.

But they didn't expect that there was still a mistake in the things that His Highness handed over to them.

"It's a bit of an error, but it's ready for mass production!"

Zhu Cijiong didn't care, he naturally knew that in this era, if he wanted to be accurate to the decimal point, he was dreaming.

He took the measuring instrument in Zhang Shili's hand, looked at it carefully, and then said:

"You can hang a small piece of paper on each measuring instrument with the margin of error written on it, so that the soldiers can also be targeted when using it."

"This solution is good!"

Ma Sanwa rubbed her hands: "These lenses are carved out by the old craftsmen one by one, and it is true that the error cannot be unified, with His Royal Highness's solution, the most troublesome problem will be solved." ”

Zhu Cijiong led everyone back, and he said, "Let's talk about muskets, how is the output now?" ”

Ma Sanwa hurriedly said: "Your Highness, the most mature is the arquebus. Although the flintlock pistol has been successfully made, the rate of mute fire is about forty percent. ”

"And the arquebus, except for the rainy weather, basically the rate of dumb fire is less than half of it, you see, is it ......"

He hesitated, His Highness had not made a mistake yet, but the flintlock pistol he made was not as good as the arquebus!

Could it be that His Highness made a mistake in his calculations?

"Third child, things can't be seen like this!"

Zhu Cijiong smiled: "What is the most important performance of ordnance?" ”

"Stability!"

He asked and answered himself, and seriously explained Ma Sanwa's confusion:

"At first glance, flintlock pistols do not have a higher firing success rate than arquebuses, but, at first, flintlock pistols have a third faster rate of fire than arquebuses. Second, unless it is a rainstorm, the flintlock pistol can be fired, and the arquebus, as long as it encounters wet weather, is easy to mute fire. ”

"Isn't a flintlock pistol much better than an arquebus?"

Zhu Cijiong looked at Ma Sanwa and laughed.

"That's the same," Ma Sanwa nodded seriously: "The old boy of Da Niu also said that the flintlock pistol should be more practical." ”

"What about the yield?"

Everyone had already walked to the war horse, Zhu Cijiong turned over on the horse, and continued to ask.

"It is still the arquebus that can be manufactured the fastest, producing more than 120 shots in a month, while the flintlock pistol is only 36 pieces."

"Because there are too few red phosphorites suitable for hair hammers."

Ma Sanwa doesn't use the hammer herself much now, this guy who has gone through shit luck is now in charge of controlling the whole situation.

After he came to Zhu Cijiong, he began to learn writing, and until now he can only write a report summary with many typos.

However, it has to be said that even though the old craftsmen were illiterate, they also had their own set of estimation methods.

This guy, although he was driven to the shelves, did a good job.

On the blacksmith's side, there haven't been any major omissions so far.

"Where's the triangular thorn?" Zhu Cijiong values this the most.

He prepared to replace the spears and spears that were customary in this era with three-edged thorns.

"Last month's output was 2,087 strokes, and Master Zhang sent us another hundred apprentices, this month's output should increase by one-third, and by next month, the output will reach about 5,000."

"It's just ......" Ma Sanwa frowned and said: "Your Highness, although the iron ore on the side of Laojun Mountain has begun to be mined, our iron ore is not available......"

Gaozhuang, the hematite of the Houwan generation, is buried relatively deep, and it is necessary to dig a downward hole and then excavate a horizontal hole.

Then it was carried to the shaft little by little by manpower, and then twisted up little by little with a roller.

In the era when there was no machinery, the output of such a mine would naturally not be too high.

"Ziyan!"

Zhu Cijiong summoned Zhang Shiling, and he said: "You tell my uncle that the iron mine is more than ten miles long, and you can choose a place to dig more shafts and send more miners. ”

Zhang Shiling nodded: "Your Highness, my eldest brother has already told my father about this matter, and the prospector is choosing a place." ”

"yes!" Zhang Shili smiled bitterly: "Your Highness, you also know that this mine is most afraid of landslides, so it will be a lot of trouble in site selection." ”

The two of them were telling the truth, once there was a landslide, the entire mine would be abandoned.

Zhu Cijiong frowned, there is a solution to this - cement reinforced concrete can be reinforced.

However, the manufacture of cement is also a difficult task.

The generation of Xichuan and Neixiang is rich in limestone.

Later, Gezhouba Group set up a factory here.

Although it is said that the high-efficiency cement of later generations cannot be made, the simple cement production method is much easier.

The limestone and clay are ground into flour and then calcined into mature material.

Grinding with clinker and slag left over after ironmaking is cement.

This is the simplest method of making cement, commonly known as soil burning cement.

The biggest difficulty in this soil method cement is grinding, and if he wants to make this, he must first drum up hydraulic machinery.

This is a little more troublesome for them at this stage.