"Yes," added Professor Gates, "for four hundred years the Roman people came here on holidays, and sometimes they had as many as one hundred and twenty-five holidays in one year. They came to be amused and entertained with games, contests, and combats between men and wild beasts; and they saw with delight many scenes of bloodshed and death, too horrible for me to describe to you." The children looked with him at the deep underground pits where the animals--lions, tigers, elephants, and other savage beasts--were kept, and at the places where two aqueducts led the water into the arena. "Those old Romans were always trying to find some new way of pleasing the people," he told them, "and sometimes they made a large lake of the arena, and had boats on the lake fighting terrible battles, in which many men were killed just for amusement. There are no walls now standing which have seen so much of the splendor and cruelty of ancient days," he added. Edith sighed. "I shall never boast about the stadium at Cambridge again," she said. "This Colosseum was built in the early days of the Roman Empire," the guide continued. "The first and greatest of the Roman emperors was Augustus, for whom our month of August was named. During his reign many buildings were repaired which had begun to crumble to ruins in the days of the republic, when the Romans had devoted most of their time and money to wars, and many other beautiful buildings were erected. It was said of this emperor that he found Rome brick and left it marble. "It was during the reign of Augustus that the most important event in the history of the world took place. Christ was born in Bethlehem. Every event which happened before the birth of Christ is said to have taken place so many years B. C. (before Christ). All dates after His birth are given as so many years A. D.--Anno Domini--(two Latin words which mean 'in the year of our Lord')." "I was born in 1893 A. D.," said Edith, "and that means that it was eighteen hundred and ninety-three years after the birth of Christ." "Yes," said Rafael, "and Julius Cæsar was killed in 44 B. C., and that means forty-four years before Christ was born." "True," said the professor, "and Julius Cæsar was born in 100 B. C., which makes him fifty-six years old when he died. Can you puzzle that out for yourselves?" Then without waiting for a reply, he continued, "The Roman Empire was very large, with vast provinces, but it also had powerful enemies. Among these enemies were the barbarians in Central Europe, and it was necessary for Augustus to protect his northern frontier with strong forces, to keep them out of the country. This he did, but we shall see that later emperors failed to see the importance of this step, and this was one of the causes that led finally to the destruction of the city of Rome and the fall of the Roman Empire.