How did the production of iron change during the Industrial Revolution?

A major change in the iron industries during the era of the Industrial Revolution was the replacement of wood and other bio-fuels with coal.

Explanation:

the triple alliance. germany and austria-hungary were already allies by 1879 when, worried about a threat from russia, they formed the dual alliance. italy joined the group in 1882. there was a concern about a possible attack from france and the alliance needed powerful friends to defend it.