Carl Hoffmann
24 x 19 cm
Geology: 1 Anthracite or hard coal, 2. Lignite or Brown coal, 3. Black or Bituminous coal, 4. Alum shale 5-6. Sulphur ore.
Geology: 1 Anthracite or hard coal, 2.
Lignite or Brown coal, 3. Black or Bituminous coal, 4. Alum shale 5-6. Sulphur
ore.