In addition to the Museum there was a splendid library, which at one time contained over five hundred thousand manuscripts--almost everything that had been written in antiquity. The chief librarian ransacked private collections and purchased all the books he could find. Every book that entered Egypt was brought to the Library, where slaves transcribed the manuscript and gave a copy to the owner in place of the original. Before this time the manuscripts of celebrated works were often scarce and always in danger of being lost. Henceforth it was known where to look for them. [Illustration: LAOCOON AND HIS CHILDREN (Vatican Museum Rome) A product of the art school of Rhodes (about 150 B.C.). The statue represents the punishment inflicted on Laocoon a Trojan priest together with his two sons. A pair of large serpents sent by the offended gods have seized the unhappy victims.] [Illustration: VICTORY OF SAMOTHRACE (Louvre, Paris) Commemorates a naval battle fought in 306 B.C. The statue, which is considerably above life-size, stood on a pedestal having the form of a ship's prow. The goddess of Victory was probably represented holding a trumpet to her lips with her right hand. The fresh ocean breeze has blown her garments back into tumultuous folds.] SCIENTIFIC DISCOVERIES The Hellenistic Age was remarkable for the rapid advance of scientific knowledge. Most of the mathematical works of the Greeks date from this epoch. Euclid wrote a treatise on geometry which still holds its place in the schools. Archimedes of Syracuse, who had once studied at Alexandria, made many discoveries in engineering. A water screw of his device is still in use. He has the credit for finding out the laws of the lever. "Give me a fulcrum on which to rest," he said, "and I will move the earth." The Hellenistic scholars also made remarkable progress in medicine. The medical school of Alexandria was well equipped with charts, models, and dissecting rooms for the study of the human body. During the second century of our era all the medical knowledge of antiquity was gathered up in the writings of Galen (born about 130 A.D.). For more than a thousand years Galen of Pergamum remained the supreme authority in medicine. ANCIENT AND MODERN SCIENCE COMPARED In scientific work it seems as if the Greeks had done almost all that could be accomplished by sheer brain power aided only by rude instruments. They had no real telescopes or microscopes, no mariner's compass or chronometer, and no very delicate balances. Without such inventions the Greeks could hardly proceed much farther with their researches. Modern scientists are perhaps no better thinkers than were those of antiquity, but they have infinitely better apparatus and can make careful experiments where the Greeks had to rely on shrewd guesses. EXTENSION OF GEOGRAPHICAL KNOWLEDGE