Just as Sinampe had predicted, although he looked like he was about to become poor, the king could still afford to design a new cannon - unlike Constantine XI who was trapped in a lonely city in the Byzantine Mountains, he had a vast territory to support him, and he could still squeeze out some money.

And the king is indeed bold, and after some general exchanges with Sinampei, he allocated all kinds of materials and venues. Originally, as a leader, he also wanted to have some in-depth exchanges with Sinampei, a "scholar from a foreign country", but because of his busy affairs, a waiter who gave orders interrupted the conversation between the two, so that the matter could not be resolved.

Although the site was still in the city because of the war, it was also satisfactory to Sinan Pei - because the shooting range for the test was placed at the back of the palace, which was not only open but also conducive to secrecy - and the officials should not forget that the palace was built on a small island in the river, unlike the outer city, if they could not pass the inspection of the Praetorian Guards, no spies would be able to come here.

However, there are advantages and disadvantages. Because it was originally the king's shooting range for archery, it was fairly well equipped and had simple ranging equipment - but the problem was that a small island in the middle of the river was sufficient for the range of the bow and arrow, but it was a little too small for the cannon. But Sinampei still came up with a solution - he took a few new students to roughly measure the speed of the river, and when he was ready to test the artillery, he fired the shells upstream of the river, and measured the range of the shells by the time when the shells flowed near the island - the cannons of this era were all solid shells, and such a simple method barely worked.

After carefully visiting the king's cannon foundry in Pali City, Sinampei shook his head and passed all the overly advanced design schemes, although he was very distressed that his brain cells had been consumed so much in vain, but he also understood that this was something that could not be helped.

It's like rifling, which can raise the range and accuracy of a cannon to a higher level, but the precision and metallurgical level of this era are completely inadequate-if you know that you can't do it, you will only embarrass yourself.

Sinan Pei reluctantly found that the production of artillery is not at all a relatively isolated technological achievement like soap, and the birth of an advanced cannon will inevitably mean all-round progress in metallurgy, chemistry, physics and other disciplines, which is not at all as easy as imagined in some travel novels.

But fortunately, Sinan Pei is a traverser after all, not to mention others, at least in terms of knowledge reserves, he has completely exploded everyone in this era.

Looking at the heavy snow falling from the sky, Sinan Pei smiled: "Let's start with making zuò iron molds." ”

"Iron model?" a group of students scratched their ears and cheeks, not knowing why.

"You're all using clay molds to cast cannons now, right?" Si Nanpei touched his chin and thought, "The clay mold can't work in such weather, how can you cast cannons?"

"Can the quality of the cannon made of iron mold pass the test?" said the flat-nosed Pol, who was the most outspoken of the students, and said what came to his mind.

"You can rest assured, in my hometown, I have already started to use iron molds to cast cannons, and I tell you that compared to clay molds, iron molds have a great advantage. Since several students raised questions, Sinan Pei took out a pen and paper and explained to them while making a schematic diagram, "The ordinary cannon manufacturing process takes at least a month, do you know why?"

"It's because the clay mold has to take a month or even longer to go through the various processes from manufacturing to drying. "If it's the rainy season and the weather is wet, it can take months – the mud won't dry out when there's plenty of moisture." ”

"Bingo!" Sinampei smiled, these students were finally teachable, and they didn't disappoint him, "But there is no problem with iron mold cannons, now that the Galledonians are fighting so fiercely, such a long process of making zuò can't guarantee the supply of ordnance to the front at all, if we start to use iron mold cast cannons, then we will have a great logistical advantage over the Galedonians." ”

A student looked at the size marked on the mold drawn by Si Nanpei on the paper, and was a little worried: "Mr. Si, this is of course excellent, but looking at your design, it seems that the cannon is a little thin? ”

"It's better to say that I'm designing too thin, it's better to say you're designing too thick. Sinampei smiled and shook his head, "Do you know why your artillery often explodes? As far as I know, although the Tuks in the East have similar problems, their artillery quality is obviously better than yours. ”

The students were eager to say that it was because of the thickness of the cannon or the quality of the bronze, but in the end they didn't say anything, but put on a look of asking for advice - they wanted to see how Sinampei explained.

"It's because of the clay mold. "The climate of the Capetian kingdom seems to me to be temperate oceanic...... Well, it basically means that it's wet and rainy all year round. Your clay molds may seem to have been dried, but in fact there is still zài moisture in them, which will turn into water vapor at high temperatures when casting cannons, which will react with your cannons and form small cavities in the cannon body - like honeycombs, causing the fragility of your cannon body. It is not conspicuous to the Tuks in the East, but it is strict to you - I reckon that the Cannonians, who live on the island, must have forged thicker cannons than yours. ”

Several students patted their heads in unison, looking like they suddenly realized.

Only the red-haired Tongwens still looked a little hesitant, "But we don't understand, I'm afraid that a few of us won't meet your requirements......

"It's not very technical, it's easy to learn. Sinampe reassured him, "Now I am not only here to complete the task assigned to me by His Majesty, but also to promote the technological achievements of my hometown—after you have learned it, it will be beneficial to this country to spread this technology." In the future, if you start casting cannons on a large scale, you will definitely become overseers or engineers. ”

Hearing such a truth, several students could only agree to it. Let's not talk about whether it is for the benefit of the public to use better technology to make murder weapons faster, but Si Nanpei's willingness to teach them this "unique cheats" already makes them very excited, as the saying goes, more skills are not pressing, and it is quite good to have a new skill, just by virtue of this, the students feel that this trip is not in vain. Not to mention, it is possible to find a decent position in the future.