They might well be scared, for they soon found that their cannon were of no more use than pea-shooters against this queer craft. The cannon-balls bounded off from her sides like so many peas. On came the monster and struck one of the ships with her iron beak, tearing a great hole in its side. Down into the waters sunk the gallant ship, with all on board. And there it lay with its flag flying like a flag above a grave. Another ship, the "Congress," was driven on the mud and had to give up the fight. There were three more ships in the fleet, but it was now near night, and so the "Merrimac," as the iron monster was called, steamed away. Her captain thought it would be an easy thing to settle with them the next morning, and very likely the people on them did not sleep well that night, for they could not forget what had happened to the "Congress" and the "Cumberland," and felt sure their turn was to come next. But, as the old saying goes, "There is many a slip between cup and lip." The "Merrimac" was to learn the truth of this. For when she came grimly out the next day, expecting to sink the rest of the fleet and then steam up to the city of Washington and perhaps burn that, her captain found before him the queerest thing in the shape of a ship he had ever seen. It was an iron vessel that looked like "a cheese box on a raft." All that could be seen was a flat deck that came just above the water, and above this a round tower of iron, out of which peeped two monsters of cannon. This strange vessel had come into Hampton Roads during the night, and there it lay ready to do battle for the Union. It was a new style of war-ship that had been built in New York and was called the "Monitor." The "Merrimac" soon had enough to keep herself busy, and was forced to let the wooden fleet alone. For four long hours these two iron monsters battered each other with cannon balls. Such a fight had never been seen before. It was the first time two iron-clad ships had met in war. I cannot say that either ship was hurt much. The balls could not get through the iron bars and plates and glanced off into the water. But the "Merrimac" got the worst of it, and in the end she turned and hurried back to Norfolk, from which place she had come. The "Monitor" waited for her, but she never came out again. Soon afterwards the Confederates left Norfolk and sunk their iron ship, and that was the last of the "Merrimac." When the news of this wonderful sea-fight got to Europe the kings and ministers of war read it with alarm. They saw they had something to do. Their wooden war-vessels were out of date, and they went to work in a hurry to build iron-clad ships. To-day all the great nations of the earth have fleets of steel-covered ships-of-war, and the United States has some of the best and strongest of this kind of ships.