It was a little house that could dig up earth on its own, mix it with the alchemical reagents provided in its jars, and produce enormous concrete-like stone bricks... Beneath it were crawler-track-like feet, with crane-like legs mounted on the tracks. They automatically rose and lowered, stacking the concrete bricks one by one in their designated positions.
There was no one operating the little house. A few alchemy apprentices were merely responsible for leading it along, and their brisk steps showed that it took no effort at all.
The massive city wall the Ster Family was building along the foot of the mountain stood a full fifteen meters high. First, they laid three stone bricks on each side, each three meters long, one and a half meters wide, and one meter high, leaving a three-meter-wide gap in the middle. Then, they added metal blocks of the same size to both sides of the concrete bricks before coating the outer wall with a layer of paint.
The top of the thirty-meter-high wall was no different from an ordinary Great Wall. One metal brick and one concrete brick formed a three-meter-high battlement. The crenellations had no concrete bricks, though the metal bricks remained. These metal bricks had been specially made... There was a ten-centimeter observation slit in the middle, with small windows on both sides that could be pushed aside.
What surprised Hill was that every metal crenellation had its observation window opening in a different position... It was probably to prevent enemies from memorizing them and hiding outside the windows to launch sneak attacks.
In the completed area, Hill saw only one auxiliary building. It seemed intended to house automatic offensive magic weapons... Several alchemists were inside calculating distances and directions.
Although the old, simple stone outer wall could still have