The Romans also showed their practical minds by making two very important city improvements. If you live in a city, you turn on a spigot and you get plenty of pure water whenever you want it. The people in cities at that time, however, usually had to get their water both for drinking and for washing from wells or springs near-by. These springs and wells often became dirty and made the people very sick. And so every once in a while because of such dirty water there were those terrible plagues, those terribly contagious diseases like the one I told you about in Athens when people died faster than they could be buried. [Illustration: Roman Aqueduct.] The Romans wanted pure water, and so they set to work to find lakes from which they could get pure water. As oftentimes these lakes were many miles away from the city, they then built big pipes to carry the water all the way to the city. Such a pipe was not made of iron or terra-cotta as nowadays, but of stone and concrete, and was called an “aqueduct,” which in Latin means “water-carrier.” If this aqueduct had to cross a river or a valley, they built a bridge to hold it up. Many of these Roman aqueducts are still standing and in use to-day. Now, up to this time waste water, after it had been used, and also every other kind of dirt and refuse, was simply dumped into the street. This naturally made the city or town filthy and unhealthy and was another cause of plagues. But the Romans built great underground sewers to carry off this dirt and waste water and empty it into the river or into some other place where it would do no harm and cause no sickness. Nowadays, every large city has aqueducts and sewers as a matter of course, but the Romans were the first to build them on a large scale. One of the most important things that Rome did was to make rules that every one had to obey; laws, we call them. Many of these laws were so fair and just that some of our own laws to-day are copied from them. All the cities and towns of the Roman Empire had to pay money or taxes to Rome. So Rome became the richest city in the world. Millions of this money, which was brought to her, was spent in putting up beautiful buildings in the city, temples to the gods, splendid palaces for the rulers, public baths and huge open-air places called amphitheaters where the people could be amused. The amphitheaters were something like our football and baseball fields or stadiums. They did not have football or baseball, however. They had chariot-races, and deadly fights between men, or between men and animals. Chariots were small carts with large wheels drawn by two or by four horses and driven by a man standing up. Perhaps you have seen chariot-races in the circus.