The earth contains many mineral substances beneath its surface, which
are useful to man. These substances are dug out, and thus immense mines
are formed. Gold and silver are obtained in great quantities in South
America. Iron, the most useful of metals, is obtained in various parts
of the world. Annexed is a representation of the iron mine at Dalmora,
in Europe. The iron ore is not dug out as in mines of coal, tin, &c.
but is torn up by means of gunpowder.
[Illustration: IRON MINE.]
The descent into this mine is by means of buckets attached to ropes.