The basis of any civilization's science is that civilization's number system. The famed Roman Numeral system consisted of the following symbols and the corresponding numbers:
| I | V | X | L | C | D | M |
| 1 | 5 | 10 | 50 | 100 | 500 | 1000 |
Converting large and complex numbers to Roman Numerals in one's head can often get quite unwieldy. To this end, we provide an easy to use converter: type in a regular number here and it will be "translated" into the corresponding Roman Numeral
The Romans were a civilization of engineers and builders. They improved on the making of cement. Before, limestone was dried until all the water locked in it was evaporated, and it turned into powdered lime. The lime was mixed with sand to make mortar for bricks, and with sand and gravel to make concrete. The Romans added pozzolana, which was a fine grained volcanic sand that was very hard and could resist the wear and abrasion better than lime. The Romans made their bridge piers from pozzolana concrete to keep the sand from river currents from eroding the foundations of the bridges.
They applied the knowledge gained by other civilizations to their uses of building bridges, roads, and other structures. For example, the Romans gained much of their engineering knowledge from the Etruscans. The Romans used the Etruscans' keystone arch which allowed for strong and durable bridges. The Romans looked to build a bridge strong enough to stretch over long distances while handling heavy loads. This was not easily accomplished, because when a bridge is built with a piece of stone bridging a space between two supports, a heavy weight in the middle will be too heavy and break the bridge. They resolved this problem by using what is called the voussoir arch. This was half a circle of tapered stone blocks arranged together. The ends stood on piers made of stone blocks mortared together with pozzolana cement. The arch would be covered with stone blocks cemented together to make a flat surface. The weight of the stone and concrete of the bridge itself compressed the tapered stones together. This made the arch a very strong structure, one able to withstand heavy loads.
The Romans also designed roads to help bring the empire closer together. The roads were supposed to be durable during all sorts of weather, to allow the army to travel fast across them. Thus, the roads had to be well drained so that rainwater would not build up and weaken them. The roads sometimes had to be built on wet or marshy ground but could not collapse under the weight of the army and its wagons. Thus the roads were constructed upon a foundation of rock.
The Romans used their engineering skills to plan their cities, which differed from the days when cities would just grow around a body of water. The Roman engineers used a basic plan. Two main streets were laid out, perpendicular to each other, forming an intersection in the middle of the city. These streets extended to the outside of the cities to the pomerium, the outer defensive wall guarded by strong gates. It was to keep away hostile barbarians or rebel army generals. Aqueducts provided water to fill the city cisterns and the public fountains found on one corner of each block or insula. The Romans also had pipes supplying water to private homes. They even paid water bills: engineers could calculate water usage by measuring the diameter of the pipes tapping into the city water supply and knowing the number of feet the private water service pipe was below the level of the cistern.