Our knowledge of Greek fighting ships--thanks to Greek literature--is fairly full. In the time of Homer, about ten centuries before Christ, Greek men-of-war carried crews of from fifty to one hundred and twenty men, nearly all of whom took part in the labor of rowing. A military boat called the "bireme" came into use in Greece about six or seven centuries before Christ. The word means a vessel with two rows or banks of oarsmen on each side, one row above the other. This disposition of rowers was evidently for the purpose of securing the largest possible number in the least possible space. It is probable that the Greeks did not originate the bireme, but borrowed the idea from the Phoenicians or possibly from Egypt. When Athens was at the zenith of her glory, the principal war vessel was the "trireme," a ship with three rows of oarsmen to the side, each rising above another. Larger ships were subsequently constructed with four, five, and even sixteen banks of rowers to a side, tier above tier. The Romans, although they were so powerful in land warfare, were not strong in naval achievement until after the First Punic War. In this war they learned the art of naval construction from their enemies, the Carthaginians. A Carthaginian "quinquereme," or boat with five banks of oars, drifted to the Roman coast. The Romans copied it, set up frames on dry land in which crews were taught to row, and in sixty days from the time the trees were felled they had built and manned a fleet. Later the Romans used grappling hooks with which they bound together their own and an opposing ship. They then boarded the enemy's vessel and carried on the fight at close quarters. These tactics gave the Romans command of the sea, and their war galley came to be the supreme object of terror in the naval history of Roman days. Sails and wind superseded rowers as the motive force of ships. Then came steam. But after gunpowder and steam had worked a revolution in the modes of naval combat, vessels of war continued to be made of wood. The first fight between iron ships in the history of the world was fought on the ninth of March, 1862, in Hampton Roads, near Norfolk, Virginia, during the Civil War in America. The battle was the combat between the _Merrimac_ and the _Monitor_. This engagement marked the end of wooden navies. Thenceforth the nations of earth were to make their warships of iron and steel.