Four days later, the back yard of the firing room in the north slope mine.
Two circular pits were excavated in the courtyard, each narrowing from top to bottom. The front section had an inner diameter of about twenty centimeters, gradually expanding to twenty-six centimeters at the rear. These pits served as molds for Roland to cast cannon casings. The inner walls had been baked by Anna, with the surface soil fused into a solid mass, forming a protective shell. The chambers were designed to be oriented downward to ensure optimal wall quality during casting, while the upper sections contained more slag and air bubbles. All dimensions were calculated based on cannonballs. Roland recalled that historical references to six-pound and eight-pound cannons were named after their weight. He first cast iron balls of twelve pounds each, then used their diameters and the barrel wall thickness to determine the mold's inner diameter.
With no measuring tools available, Roland devised his own standard. He took a piece of iron about the width of his ring finger's nail as the base unit—1 centimeter—and used it to create iron bars of other sizes, each marked with dividing lines.
Using a crude iron rod ruler, he measured the twelve-pound iron ball's diameter at approximately twelve centimeters. He determined the thinnest section of the barrel wall to be four centimeters thick, while the rear chamber wall was expanded to seven centimeters to prevent barrel explosion, thus calculating the mold's inner diameter. Regarding length, although he knew artillery had a bore-to-caliber ratio, only the main gun ratios of battleships and main station tanks remained in his memory. As for antique front-loading cannons, he was completely unaware of them.
Given that shorter barrels mean lighter weight and less material usage, Roland casually selected 1.5 meters as the standard. Should the test firing results prove unsatisfactory, adjustments can be made later.
When cannons were first invented, they were constructed by encasing wooden cores with iron bars and powder, reinforced with iron hoops, and finally fired to remove the core—much like storage barrels. Roland, of course, recognized the risk of air leaks and barrel explosions in such cannons, so he directly adopted the process of integral casting and boring. For steam boring machines, whether drilling six-pound or twelve-pound cannons, the difficulty was essentially the same.
Guided by the principle that caliber equates to justice, he naturally opted for the twelve-pound cannon with its larger muzzle and thicker barrel. Any larger would make it impractical for field artillery. Whether the projectile weight was measured in lead or iron balls was irrelevant—what mattered was its range. After all, he was drawing lessons from history, not replicating historical models.
"Begin," Roland said, taking a deep breath. Anna nodded and grabbed a steel ingot, which hung above the cave entrance. Green flames erupted as the ingot rapidly turned red, then melted into a thin stream of molten steel cascading into the cavern. The surface glowed orange-red, while the core glowed white-hot, its brilliance blinding. To protect the Witch's vision, Roland had erected a support beam at the cave's edge. She could simply position herself and rest her arm on the cushion, avoiding the need to watch the molten steel flow into the cave.
These steel ingots were accumulated gradually over time. While Anna couldn't single-handedly usher in the Great Steelmaking Era, small-scale production was no challenge for her. Once the most difficult temperature hurdle was overcome, she could produce high-quality steel using the steel smelting method.
This is why Roland dared to design his own gun barrel dimensions. Steel cast barrels clearly outperformed cast iron and bronze ones in strength. Even if the dimensions were off, the cannon wouldn't easily blow up.
The molten steel level kept rising, while the remaining ingots dwindled at an alarming rate, a sight that left Roland with a pang of sorrow. When would he finally be able to build a cluster of chimneys and blast furnaces across his domain, producing an inexhaustible supply of steel? For a long time, steel output had been a key measure of a nation's power, and now he could feel it firsthand.
As the two molds filled to the brim, Anna's cheeks flushed crimson. Roland reached for a handkerchief and gently wiped the sweat from her nose. Initially, Anna had resisted, but now she lay motionless, eyes closed, as Roland proceeded with his ritual.
Her drooping bangs cast a crimson hue against the molten steel, and the softness of her neck made one want to take a bite. From her vantage point, the slender, half-revealed collarbone peeked through the garment, entering her field of vision. As they drew closer, the faint fragrance emanating from her body could be detected.
"Ahem, alright..." Roland tucked his handkerchief away, suppressing his mounting agitation. "That's all for today. Well done. I'll order an extra portion of black pepper steak for you at dinner." Not now, he thought. This might seem like exploiting someone's vulnerability. Wait until she's truly free...
Anna opened her eyes. Though the sweat had been wiped away, her face appeared even redder than before. She nodded at Roland and gave a soft 'hmm'.
...
Over the next few days, Roland shuttled between Castle and the North Slope Mines.
Besides the barrel, he also needs to make enough boring tools.
This drilling tool is manufactured using a process similar to that of cannon barrels, with identical diameter and projectile specifications. After being removed from the mold, Anna reheated it and shaped it using an iron hammer. The tool's appearance differs significantly from conventional spiral cutters, resembling a blunt iron rod at first glance. The only distinguishing feature is a notch carved into the top to discharge metal shavings. Finally, quenching is applied to enhance the hardness of the boring cutter.
Unlike modern boring machines that require high-precision drill bits, Roland needed only a simple iron rod to drill holes. Given the high wear rate, he and Anna crafted five rudimentary boring tools within a week. Prior to this, the steam boring machine had already proven its capabilities—producing iron gun barrels from two per month to ten daily.
Once all preparations were complete, the cannon blanks were dug out of the pit by miners, the surface slag was removed, and then loaded onto carts for transport to the blacksmith shop.
These two cannon barrels nearly depleted all the steel Roland had saved up—truly a priceless treasure. During transport, Prince ordered Carter and two Knights to guard the entire journey, which Chief Knight found unnecessary. Who would steal such a heavy load?
At Prince's request, the blacksmiths leveled and polished the cannon's exterior. After the grinding process, they rushed the work to the castle's rear courtyard. By then, the two solid steel rods had developed a deep gray hue, radiating a heavy metallic sheen.
Roland eagerly switched to the boring cutter and, together with Carter, secured the cannon blank in place, positioning the cutter tip precisely at the center of the steel rod.
At this historic moment, Roland pulled the valve of the steam engine. The boring cutter began to rotate slowly and soon reached a steady speed.
"Cut in!" Prince shouted.
Chief Knight manipulated the sliding base to regulate the contact depth between the cannon body and the boring tool. The moment the tool tip touched the barrel, the piercing noise instantly drowned out the steam engine's roar. Lard, serving as a lubricant, was forced into the bore, spewing black foam and coiled metal wires. The Witchs who had gathered in the wooden shed dispersed, leaving only Lightning standing firm. To her, these darkened mechanisms seemed more captivating than any landscape.