The Invention of the Arch

The arch is possibly the most significant element of architecture perfected by the Romans. It in itself has led to the inventions of vaulted ceilings, and domes. As these aspects got higher and higher, arches were then created in the form of buttresses to maintain the structural integrity of these edifices while adding to the dazzling set of features on these monolithic works of art. The Beauvais Cathedral in France is a incredible example of the evolution of Roman archwork. As shown in the image, the buttresses rise all the way to the roof using the basic principals of the arch to support the behemoth weight being pressed down and outwards by the force of gravity. The vaulted ceiling itself is an adaptation of the classic arch since in essence it's an extravagant show of arches criss-crossing the ceiling blending aspects of art and basics of structural integrity.
The dome is another extension from the arch. Essentially, if you had two symmetrical arches crossing each other in a perpendicular manner, you'd have four quadrants. Similar to cutting pizza slices, theoretically, you could cut an infinite number of slices. Using this principal, you could fill all the gaps in the four quadrants with and infinite number of arches, thus resulting in the dome. The most famous Roman example of the dome is its Pantheon with its famous oculus. To avoid the possibility of collapsing in on itself (before the invention of the buttress), the unknown architect designed in the inside with a series of ribs creating trapezoid shapes as shown in the image. This saves overall weight and the oculus doubles as a material saver by being the temple's main source of light.
Possibly the largest example of the arch is the Roman aqueducts. These engineering marvels were precisely measured and created to deliver water from large sources to the bathhouses of Rome. To overcome the obstacles of deep valleys and gorges, the Romans made strong use of their arches. Not only do they look gorgeous, but they save immense amounts of material while being structurally sound. All in all, the arch is an extremely important aspect of Roman architecture since it has countless uses that have been shown over the course of history.