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Black Horse Island.
Liszt was inspecting the mining of volcanic glass ore, which was quite interesting. It was hard on the outside, filled with bubbles on the inside, and had a clear boundary with the surrounding soil and rocks.
As long as one dug deep into the earth, reached the basalt columns, one could follow the cracks to find the volcanic glass.
So, once a thousand serfs mastered the excavation technique, they turned over the land along the low-lying areas. Not only did they unearth a large amount of volcanic glass, they also managed to convert the land into farmland in the process.
