Today, iron and steel are invaluable for construction industry. Do you know why? The framework of steel girders that you see in buildings under construction are designed to bear the weight of a building. Without this framework, buildings made from just stone or brick would have to have very thick walls at the bottom, which would limit their height.
Iron too, plays an important role in construction. The first iron bridge was built in 1772, and in 1818 the first iron ship was launched. Railways also depend on iron, and iron construction reached the height of elegance in the 300 meter high Eiffel Tower in Paris, which is built of latticed iron. The uses for iron and steel in construction are many, and continue to expand as the years go by.
