Chapter 25: The Stone Thunder!

"Master, why are you tinkering with this piece of junk?"

Hu Dayong stood by, clutching his fire-lance and frowning at the scorch marks on the ground. With no one else around, the title "Master" rolled off his tongue with practiced ease, his voice laced with a hint of shameless flattery.

"This three-eyed gun is impractical. It loads too slowly and the range is poor. It’s nowhere near as reliable as a bow and arrow."

"It’s impractical because the gunpowder is flawed." Lin Chuan poked the embers with the tip of his dagger and smiled. Having corrected him twice already, he had given up on stopping Hu Dayong from calling him "Master."

"The saltpeter isn't purified, the sulfur contains arsenic, and the charcoal is just wood that hasn't been burned through. Taking this to war is less effective than throwing rocks."

"The gunpowder is flawed?" Hu Dayong blinked, stunned. His master was truly formidable—how did he know about all of this? Though he didn't fully grasp the technical details, it all sounded incredibly profound. Impressive! Truly impressive...

"So, what is it that you're working on, Master?" Hu Dayong’s eyes were brimming with curiosity.

Lin Chuan didn't answer. He pondered for a moment, then gave an order: "Go find me two stonemasons."

"Stonemasons?" Hu Dayong was taken aback. "Master, to make gunpowder, you need pyrotechnicians. Stonemasons only know how to chisel stone..."

"Exactly. I need them to chisel stone," Lin Chuan replied.

He wasn't looking for stonemasons to adjust his gunpowder ratio; he wanted to make stone mines. He intended to handle the gunpowder experiments himself, as the risks were too high to entrust to others. Once the tests were successful, he could then have the pyrotechnicians replicate the process. But the stone mines could only be fashioned by stonemasons.

The idea came from a war film he had watched in his past life. In the movie, the common people used their wisdom and their hands to turn ordinary rocks into lethal weapons. As enemy troops marched through the mountains, they would inadvertently trigger traps, causing boulders to explode with a roar, leaving their enemies screaming and bloodied. Those stone mines, buried deep or hidden by the roadside, became the invaders' worst nightmare.

Lin Chuan still remembered the details from the film: the stonemasons would carve the bluestone into rounded shapes, hollow them out, carefully pack them with gunpowder, and insert a fuse. It was a crude craft, yet it held ingenious designs. The triggering mechanisms were diverse—pull-wires, trip-wires, pressure plates, and even traps designed to be set off by livestock or natural occurrences.

"Squad Leader, the stonemasons are here!" Hu Dayong’s voice pulled Lin Chuan back to reality.

The two stonemasons stood nervously to the side, clutching their chisels and hammers. Lin Chuan drew a simple sketch on the ground and said in a low, steady voice: "I need you to carve a batch of stone spheres, hollowed out in the middle, large enough to hold five pounds of sand. Remember, the opening must be a perfect, airtight fit. Not a single spark can leak out."

Old Li, the stonemason, frowned as he studied the sketch. "Squad Leader, this thing... it’s not hard to carve, but once it’s hollowed out, the stone walls will be thin and prone to cracking."

"Wrap them in wet cowhide while you carve, and pour water as you work," Lin Chuan said, recalling a documentary on how the ancients carved stone sarcophagi. "If that doesn't work, make them square. It’s easier to hide the edges."

Old Li scratched his head. "Squad Leader, what are these for? They aren't as good as swords, and they're a pain to lug around."

Hu Dayong gave him a kick. "Just do as you're told! Is what the Squad Leader is planning something a geezer like you can fathom?"

"Yes, yes, of course..." Old Li stumbled but nodded eagerly, not taking offense. When he had first arrived at Iron Forest Fort as an auxiliary soldier, he had been terrified. Now, he was familiar with everyone; they all knew the Squad Leader was approachable, and although Corporal Hu had a fiery temper, his heart was in the right place. The other stonemason chuckled along.

Lin Chuan patted them on the shoulders. "Once they're done, you'll know exactly what they're for. But one thing!" His gaze turned sharp. "From now on, this stays buried in your bellies. If a single word leaks out, you'll lose your heads!"

The stonemasons nodded hurriedly.

...

Once the stonemasons left, Lin Chuan began preparing the new gunpowder. In this era, gunpowder was not a rarity, but its application remained stuck at the level of a mere "noisemaker." The root cause was the volatile, unpredictable nature of the dark brown powder: the saltpeter was unrefined, the sulfur-to-carbon ratio was chaotic, it clumped into mud when damp, and it was prone to exploding in the barrel when dry. A slight misstep could lead to a catastrophic explosion that would incinerate the user.

In the Great Qian Dynasty, from the official Bureau of Ordnance to the rural workshops, no one cared to investigate why some gunpowder only smoked while others could shatter rock. They simply followed the old ways of grinding and mixing, calling it "refining."

Lin Chuan had Hu Dayong send men to the mountainside to dig up nitre-rich soil and pour it into clay jars. After boiling it with water and filtering it through linen, the amber solution slowly turned clear. Hu Dayong crouched nearby, fanning the flames. "Master, why does this saltpeter water look like honey?"

"This is far more precious than honey." Lin Chuan scooped up some of the solution with a wooden spoon and observed the suspended particles against the candlelight. "The Ordnance Bureau is too stingy to spend the effort on purification, which is why their gunpowder is like muck."

"Wait? We're making gunpowder?" Hu Dayong gasped. His fan fell into the charcoal brazier, and sparks singed his trouser leg. He scrambled to beat out the flames, keeping a safe distance from the clay jar.

"The people at the Ordnance Bureau only know how to pad the gunpowder with mud and sand to make up the weight." Lin Chuan filtered the clear liquid through the linen, rubbing the white crystals on the fabric with his fingertips. "Smell this. Authentic saltpeter should be bitter, but their gunpowder reeks of urine. They probably just soaked the soil in urine to save themselves the trouble of boiling it."

"Urine? Can urine explode?"

"Shut your mouth!"

After the filtrate cooled, prism-shaped crystals formed in the porcelain basin. Lin Chuan took a scale and measured out seven taels of saltpeter, two taels of sulfur powder, and one tael of charcoal powder. This was the ratio he had adjusted based on his memories from his past life.

He poured the three powders into a wooden mortar, wrapping the pestle in a glove. This process was critical. Iron tools were strictly forbidden, as they could cause a spark and ignite the powder. As the pestle rose and fell, fine dust rose like a mist, and Hu Dayong couldn't help but hold his breath. Finally, the powders merged into a uniform, dark brown mixture.

"Let's go to the training ground."

Lin Chuan divided the powder into two portions. He wrapped the larger portion in coarse cloth to make a simple explosive pack, and wrapped the smaller portion in cotton thread soaked in pine oil to create an improved fuse.

As Hu Dayong dug the pit, his hands trembled on the shovel. "What are you shaking for? Did your hands shake this much when you stole the General's wine?"

"Is that the same thing?" Hu Dayong pulled a long face. "If this thing goes off early, the two of us will be drinking with the King of Hell."

"Enough talk." Lin Chuan kicked the edge of the pit. "Dig deeper and pack it tight."

The explosive pack was buried at the bottom of the pit, covered with three inches of tightly packed soil, with a thirty-pound stone placed securely on top. Lin Chuan pulled out a flint, lit the fuse, grabbed Hu Dayong by the collar, and bolted.

The two ran thirty paces away and crouched on the ground, staring at the stone. Hu Dayong counted his heartbeats. One, two, three... Ten seconds passed, and the stone didn't budge. He swallowed hard and snuck a glance at Lin Chuan.

Lin Chuan was also feeling a bit puzzled. After all, this was his first experiment with home-made explosives. The ratio should have been correct... the sulfur purity was low but shouldn't have mattered much... the charcoal was fine... Could the fuse have gone out?

"Master, could it be that..."

Before Hu Dayong could finish, a single look from Lin Chuan silenced him.

"Shh!"

Lin Chuan frowned. The sulfur was bought from an apothecary, the charcoal was burned himself, the saltpeter was dug from the mountain... It should have been fine...

"BOOM!"

A sudden, thunderous roar erupted from the ground. A wave of air and flying dirt rushed toward them.