Arch

architecture · engineering · history

Ancient Roman invention. While arches existed as decoration thousands of years earlier, the Romans were the first to use them to support heavy weight in buildings and bridges around the 4th century BC, which was a brilliant engineering breakthrough.

Curved for strength. The curved shape of an arch is magic for supporting weight. The curve spreads the force outward and downward, making it much stronger than a straight beam could ever be.

Bridges and buildings. Arches let builders create huge open spaces underneath, which is why you see them holding up bridges, tunnels, doorways, and the roofs of grand buildings like cathedrals.

Decoration too. Before arches were used to support weight, people decorated with arch shapes as far back as 4000 BC, just because they looked elegant and fancy.

Pressure spreads outward. When you put weight on an arch, the curve pushes the force sideways and down toward the ends, which is why the base of an arch needs to be strong and sturdy.