In the course of his career Guido really painted in three styles. His earliest pictures are the strongest; those of his middle period are weaker, because he seemed only to strive to represent grace and sweetness; his latest pictures are careless and unequal in execution, for he grew indifferent to fame, and became so fond of gaming that he only painted in order to get money to spend in this sinful folly. His masterpiece in Rome was the "Aurora," on a ceiling of the Rospigliosi Palace; it represents the goddess of the dawn as floating before the chariot of Apollo, or Phoebus, the god of the sun. She scatters flowers upon the earth, he holds the reins over four piebald and white horses, while Cupid, with his lighted torch, floats just above them. Around the chariot dance seven graceful female figures which represent the Hours, or Horae. I have been asked why seven was the number; the ancients had no fixed number for the Hours; sometimes they were spoken of as two, again three, and even in some cases as ten. It has always seemed to me that ten was the number chosen by Guido, for in that case there would naturally be three out of sight, on the side of the chariot which is not seen (Fig. 51). [Illustration: FIG. 52.--BEATRICE CENCI.] The portrait of Beatrice Cenci is another very celebrated picture by Guido; it is in the gallery of the Barberini Palace, in Rome (Fig. 52). The interest in the portrait of this unhappy girl is world-wide. She was the daughter of a wealthy Roman noble, who after the death of her mother married a second time, and treated the children of his first marriage in a brutal way. It is even said that he hired assassins to murder two of his sons on their return from a journey to Spain. The story also relates that his cruelty to Beatrice was such that, with the aid of her step-mother and her brother, she killed him. At all events, these three were accused of this crime and were executed for it in 1599. Other accounts say that he was murdered by robbers, and his wife and children were made to appear as if guilty. Clement VII. was the pope at that time, and in spite of his knowledge of the cruelty of the father he would not pardon them, though mercy was implored of him for this lovely girl. The reason given for this action of the pope's is that he wished to confiscate the Cenci estates, which he could do if the family suffered the death penalty. So many reproductions of this sad face have been made that it is very familiar to us, and almost seems to have been the face of some one whom we have known.