Niu Ida flew around in the hole, inspected the various warehouses of the "New Eagle's Nest" base, counted the material reserves, and calculated an account:

The people of the Northern Lizard Fortress can be transferred back in a batch - farming is the top priority, and it can't be stopped, so you have to leave some more kobolds, cultivate the fields, collect seeds, and don't have too many barren fields there anyway, it's not a problem. Pen "Fun" Pavilion www.biquge.info

Then a handful of carpenters stayed, and continued to cottage dhows, not missing these hundred and ten people.

Building docks and cutting timber, although also important, is not a high priority, and the work can be done in the back.

Forget it, just take advantage of the fact that the troops have not yet been dispatched, collect timber in the Thousand Caves and hills, there are so many mountains in the east, and the cut down trees are thrown into the Mo Emerald River and float down the river to the Lizard Fortress, I am so witty!

This saves a lot of manpower.

Here in the Thousand Caves and Hills, a lot of saltpeter and sulfur have been collected - these things are still quite abundant locally, either as medicinal materials or as materials for leather making. It shouldn't be a problem to support a big war - if gunpowder weapons were already widespread.

Then, Tesfeier's nitrate field and Guan Renxiu's chemical experiment can be suspended first, and the 'New Eagle's Nest' only needs to leave the best group of carpenters and blacksmiths here, plus a small number of troops left behind, and all the others can go into battle!

Addition, subtraction, and dispatching 1,500 dog heads is not a dream!

Anyway, it's a wave, the grain is sufficient, and there is no need to send a transport team for logistics, and these 1,500 dog heads can be piled up to the front line, just waiting for the bankruptcy to be finished...... Ah no, after the fight, they all went home to farm and continue to climb the technology tree. The Brave Hill is soft, if you dare to do it again, you can destroy it easily, it's so capricious!

Well, the house and car are all chosen, and we are waiting to buy lottery tickets...... The premise of everything is that gunpowder weapons can be mass-produced in a short time, and if they can't do it, everyone can only make a final choice: merge with their neighbors, or go to the northern swamps to touch toads and eat.

On the other end, Brother Long was very confused: Where are the people? Where have they gone? Didn't you say that you want to be fired? I have called all the younger brothers!

Everyone's mood is a little complicated, and no one has time to pay attention to him.

Youth is used to be confused, especially Brother Long, there are really not many times when you are not confused, just get used to it!

Niu Jingtian's thinking is very clear, it is nothing more than "the house and car are chosen, everyone go to buy lottery tickets and wait to win the jackpot", but his plan is still a little feasible:

In the past two months, Xu Ping'an's "cannon project" has achieved many results, and now the technology is close to maturity.

In the early days, several bronze cannons were built, with various shapes and specifications - bronze has a low melting point and strong toughness, which is more suitable for tossing.

After putting a lot of cannons, the appropriate size and proportion of each component were roughly figured out, and later the steelmaking technology was greatly improved, and these copper cannons were melted by the stingy Xu Ping'an, and the copper coins were made to buy materials, which can be regarded as making the best use of things.

Because the firing range of the cannon does not need to be too large: the aiming is basically by sight, the accuracy is basically blind, one kilometer is long-lived, and two kilometers are wasted. In the end, the golden ratio of 15 times the diameter was chosen - that is, the length of the barrel is a multiple of the diameter of the shell.

Because at the beginning, I wanted to build a 12-pound cannon (the weight of the shell was about 5.4 kg), and in the end, I made a lot of money, using pig iron with the least impurities and good composition, using the iron model method, pouring four test products of different specifications, and using two furnaces of molten iron.

In order to ensure the manufacturing speed and yield, the cooling technology of the barrel center was also experimentally added - that is, the flowing water heat dissipation structure was added to the mold in the center of the barrel, and the students who had played with the water-cooled chassis must be able to imagine that in history, this trick was called the Rodman method, which was invented by the Americans.

Because under the condition of natural cooling, the outer wall of the barrel will be cooled first because it is easy to dissipate heat, and the inner wall of the barrel will generally be cooled last, resulting in thermal expansion and contraction, and the difference between the internal and external cooling speed is too large, and it is easy to crack and become waste.

As long as the casting mold of the gun chamber is added with a water cooling device in advance, this problem can be greatly reduced, but the cooling rate is equally particular, and the internal and external cooling of the gun barrel needs a suitable speed ratio, otherwise it will be the same crack for you to see.

Fortunately, the 12-pounder cannon is not a big guy, and Xu Ping'an adopted a conservative cooling speed and successfully passed the level.

The cannon is basically satisfactory, although the appearance is a little vulgar, but the power is definitely worth the money, Xu Anping used a double-strengthened black powder test firing, and still withstood the test, and in the end, except for one cannon used to test the life, it was scrapped, and the other three can be taken out and used.

But there is also a problem - these cannons are too heavy, weighing more than 700 kilograms (the 12-pounder bronze cannon is about 550 kilograms, and the iron cannon is much heavier than the bronze, but Xu Kunlun has no experience and makes the cannon thicker).

Plus the artillery carriage artillery carriage, up to more than 900 kilograms, now there are not enough livestock to pull it, with ordinary manpower to pull the cart, to walk the rotten road in the field, at least more than 40 people can walk, not to mention kobolds.

A cannon suitable for kobolds should naturally be something that kobolds can also drag.

After building two batches of cannons, Xu Ping'an's experience has also increased greatly, and many ideas have been perfected. As a result, a well-thought-out and reliable cannon debuted - a 6-pounder smoothbore gun.

This cannon has not only improved the technology, but Xu Ping'an even drummed up an innovative gameplay that has never appeared in history.

The barrel of this cannon is divided into two layers, and the inner barrel is made of steel - first an iron rod is poured, and the kobolds polish it finely, and then on this iron embryo, the kobolds are divided into several groups, wrap the hot steel plate around the embryo, knock out the inner ring of the barrel, and finally take out the iron mold, and a "very thin" steel cannon comes out. This step is basically an old-fashioned process, except that it is very labor-intensive, and it is not too difficult.

Then this thin pipe is combined with the iron fan prepared in advance, and the pig iron water is poured into it, because the melting point of the steel is higher than that of pig iron, there is no need to worry about the deformation of a layer of barrels inside. In this way, the second layer of pig iron cannon barrel is formed, which tightly wraps the steel cannon barrel inside, and the physical properties are not bad.

This design is labor-intensive - using a pile of thin steel sheets to hammer out an inner cannon barrel raw, and to ensure quality, it takes too many craftsmen.

However, the benefits are even more, the double-layer barrel, in which the inner layer is still steel, can withstand greater chamber pressure, and also greatly saves the amount of steel, which is equivalent to reducing the weight!

At the same time, the bore accuracy is much higher than that of a purely cast gun, and there is no need for such a long barrel, which in turn reduces the length of the gun and again saves weight.

The final product is:

Unnamed six-pounder field gun, caliber 90mm, body barrel length 1350mm, total gun length 1500mm, steel double-layer body tube, gun body with several reinforcing ribs, the thickest part of the gun tail about 200mm, decreasing forward.

The mass of the gun body is 250 kg, the weight of the gun carriage is 100 kg, the gun carriage and tail brace are single, double wheels, the structure is iron-clad reinforced wooden wheels, there are simple high and low machines, and there is no horizontal direction machine.

The shells consisted of spherical cast-iron bullets with wooden pallets, and scattered shells with wooden pallets - 18 buckshot bullets wrapped in tin buckets. The propellant is a fixed spider silk medicine bag - a cloth pouch woven from spider silk with granular gunpowder inside.

The firing method is to draw the tube to ignite, and inside is iron wire, quartz sand, gunpowder and the like, and as soon as the rope is pulled, it will ignite - theoretically.

The artillery wagon, the front car, and all kinds of baggage, weighing 500 kilograms on the march, require 40 dog heads to work together on a long-distance march on a poorly maintained dirt road.

After the test, the kobold pulls three to four kilograms, calculate the rolling friction coefficient, when pulling the car for a long distance in the field, a dog head can bear the weight of the board car of twelve to fifteen kilograms, close to 500 kilograms of big guys, 40 dog heads pull forward and push back, can insist on walking for a day.

With a sharp weapon and a murderous intent, with this seemingly mature and reliable weapon, it is no wonder that Niu Ida can't sit still: if there is a shortage of people, he will go out to catch demons, and then continue to go home and farm!

After saying hello, he flew all the way to the Lizard Fortress and began a large-scale deployment of troops.

And here, the thousand caves and hills are also all kinds of chickens and dogs.

The blast furnace of the 'New Eagle's Nest' began to work in full force, with the air regenerator, a furnace of molten iron could be produced in a day, and the frying steel and pouring pig iron were rotated, and more than a dozen 6-pound guns were built, plus a large number of iron ingots.

But the number of kobolds is there, and it is impossible for all kobolds to be artillerymen, and forming a large number of musketeers is the king.

The musket is much easier, although limited to technology, only arquebuses can be produced, but at least it can knock over heavily armored enemies, and it is a revolutionary weapon for weak kobolds.

In the process, steel sheets or wrought iron are wound around iron rods, then heated, beaten on grooved anvils, and finally a pipe is made, which is thick in the front and thick in the back.

Next, use high-carbon steel as a drill bit, polish the inner chamber of the tube smoothly, add a firing device, a front sight, and a wooden butt, which is not difficult, and the kobold blacksmith and carpenter can do it, it is only a matter of time.

The rest of the time is how to fight with the 'Hill of the Brave'.

Baron Caven and the Prophet waited silently in the town of Saka for the Thousand Caves and Hills to respond. After a week of delay, a kobold transport team that ran the transport brought a letter.

The content is simple: the archmage Tesfil agrees to send troops, but only with three months' food advances, and then a month later before he can act.

In the eyes of several people in Saka Town, except for the impossibility of food advances, everything else is good news. The biggest problem is food, and there is actually not enough here.

In this era of backward technology, grain production is actually national strength.

If it weren't for the fact that a large group of kobolds fell from the sky after autumn and accidentally cleared the demons who had been entrenched in the Thousand Caves and Hills for many years, then this year's autumn harvest would definitely be seriously disturbed by demons - just a large group of nocturnal demon bats could destroy half of the crops.