Seeing that Muma nodded, Ava quickly dropped the machete and ran over to kneel beside the fallen Senka to check.

At this time, the young Senka looked up and smiled at Ava with difficulty, then tilted his head and lost his breath.

Muma walked up to Ava, pulled the arrow out of the Senka's corpse, shook it, and said, "I gave him a chance." ”

Ava sobbed and said, "Okay, I'll go back and tell them, don't run away, don't run away..."

After a while, Duozu flew back again with a few pieces of wood, and before landing, he saw the corpse of the young Senka, nodded lightly, and grinned.

Seeing Ava slowly trimming and chopping the stakes, Duozu said, "Okay, okay, I'm tired too, and I'm carrying the wood back too fast for you to keep up with the speed of repairing." Let's go back and eat a bite to eat. Then two new slaves were selected to come out to work. ”

On the next few Earth days, according to David's design, everyone divided labor and worked together, and first built the first house at the innermost part of the cave.

After all the slaves were transferred to this house, the progress of the project was accelerated.

Soon, a total of eight rooms were built in the cave, which were not only for everyone to live in, but also reserved rooms for the storage of supplies and the detention of newly captured slaves in the future.

In the wooden house, a stove with a chimney was also built to burn wood, which not only kept warm and damp, but also served as a light and could cook something.

Then it was time to build smelting facilities such as waterwheels and large furnaces.

The role of the waterwheel was to power the blowers of the large furnace, and once the furnace was built, David planned to smelt the meteorite first, familiarize the slaves with the process, and then refine the brass.

Days passed, and after three Earth months, the slaves, under the guidance of David, built a waterwheel more than ten meters high on the inside of the waterfall, and a large furnace with a huge blower more than ten meters high.

Then, large pieces of charcoal were used as fuel to refine more production and living utensils such as machetes and iron pots.

As for whether there will be carbon monoxide poisoning or anything in the cave, David found that due to the effect of the waterfall flow, a surrounding wind will be formed in the cave, which can always keep the air in the cave fresh.

Then the copper ore was refined, and after many trials, the first brass was produced.

During this period, David and Duozu explored for mines on this Cave Island, and even flew back to the Eden Continent to find it.

While at the human base, Joseph did not prevent David from looking at the expeditionary force's various exploration results, including the results of prospecting, of course.

Prior to this, the expeditionary force had used modern technologies such as audio magnetotelluric to find a lot of various mineral deposits in the Eden continent, and of course humans would mine the nearest shallow mines, so those mines far away from the human base, David felt that they could be used.

After guiding Duozu to the approximate location of the mineral deposits in his memory, David not only checked on the surface, but also asked Duozu to dig deep underground to take samples.

As a result, David was able to discover many useful metal deposits, and asked Duozu to make landmarks on the ground of these deposits in case of emergency.

With copper and iron, David began experimenting with making smokeless incendiary ammunition to equip him with firearms in the future.

Smokeless incendiary agent is an incendiary agent made of nitrocellulose or nitrocellulose as the main raw material, and is one of the important raw materials for making ammunition.

With the assistance of Duozu and Muma, on the island and even flew back to the Eden continent, gathered all kinds of raw materials everywhere and taught Muma and the slaves to process and refine, David studied more than a dozen solar days in a wooden house used as a laboratory, and finally created a single-base incendiary drug, a double-base incendiary drug and a three-base medicine successively.

Next, David decided to make bullets for his pistol first.

No matter what style and shape of bullet it is, it is composed of four parts: a projectile, a cartridge (cartridge case), an incendiary charge and a primer.

There are different requirements for different firearms and ammunition. For example, pistols mostly use porous and fast-burning single-base drugs. The rifle uses a lightened and passivated single-hole granular single-base agent for the surface.

The primer is composed of a fire transfer hole, a fire anvil and a firing agent. Its function is to produce a flame when firing, and ignite quickly and surely***. When firing, the firing agent is ignited by the impact of the firing needle and the fire anvil, and the flame is ignited through the fire transfer hole***.

When fired, the firing pin excites the primer. The primer burns rapidly and ignites the fire cartridge (cartridge case), which produces instantaneous combustion, and at the same time produces high temperature and high pressure, extruding the projectile (warhead) from the cartridge.

Based on the above principles, David instructed the slaves to refine several copper-iron alloys with different hardness and composition, which were used to make bullet shells, warheads, and bottom fires.

Prior to this, David had instructed his slaves to make pliers, hammers, files, and other tools of various sizes out of meteoric iron.

When everything was ready, David locked himself in a rudimentary laboratory and spent a few solar days making a dozen small yellow-orange-orange bullets.

On the day of the official shooting experiment, Muma asked Zoya to catch a fat platypus and tie it to a large rock near the rocky beach outside the waterfall with a brown rope.

Under the gaze of dozens of slaves and Duozu, Zhuoya, and Muma, David slowly took out the bullets in a small yellow wooden box one by one and loaded them into the box.

Then he looked back at the open-mouthed Dozu attached to him, turned around and put the cartridge box into the pistol, loaded it, and aimed it at the platypus's head.

"Bang !!"

"Humph! Hum! ”

The first shot rang out, and the platypus had an extra hole in its head, and it fell to the ground convulsing and wailing, and blood flowed all over the ground.

Because David was not in a position to make more sophisticated explosive bullets, the platypus was only injured and did not die immediately, but even one shot was enough for the platypus.

"Ahh Wow!!! ”

There was a gasp and a low exclamation from the slaves.

Duozu narrowed his only eye, his eyes revealing a hint of alertness, his throat rising and falling, which was the characteristic preparatory action of the Uenki race before it erupted into fire.

"Bang bang bang!! Bang bang bang!! ...”

David slowly turned his gun and fired six more rounds at the rocky beach in the distance.

I saw that where the bullet hit, sparks flew everywhere, and some small stones were hit and exploded into fine fragments and powder.

Just as David was about to shoot farther away, the pistol came with a "Click!" "There was a thud.

"Dud... It seems that my handicraft is still not good. ”