Everybody opened their eyes wide and stared as at a show when they saw this strange object. They called it "a cheese box on a raft," and that was a good name for its queer appearance. For the deck was nearly on a level with the water, and over its centre rose something like a round iron box. But it had two great guns sticking out of its tough sides. It was the _Monitor_, the new vessel which Captain Ericsson had built and sent down to fight the _Merrimac_. But none who saw this little low thing thought it could stand long before the great Confederate iron-clad. It looked a little like a slim tiger or leopard before a great rhinoceros or elephant. The men on the _Merrimac_ did not seem to think it worth minding, for they came steaming up and began firing at the _Minnesota_ when they were a mile away. Then away from the side of the great frigate glided the little _Monitor_, heading straight for her clumsy antagonist. She looked like no more than a mouthful for the big ship, and men gazed at her with dread. She seemed to be going straight to destruction. But the brave fellows on the _Monitor_ had no such thoughts as that. "Let her have it," said Captain Worden, when they came near; and one of the great eleven-inch guns boomed like a volcano. The huge iron ball, weighing about 175 pounds, struck the plates of the _Merrimac_ with a thundering crash, splitting and splintering them before it bounded off. The broadside of the _Merrimac_ boomed back, but the balls glanced away from the thick round sides of the turret and did not harm. Then the turret was whirled round like a top, and the gun on the other side came round and was fired. Again the _Merrimac_ fired back, and the great battle was on. For two hours the iron ships fought like two mighty wrestlers of the seas. Smoke filled the turret so that the men of the _Monitor_ did not know how to aim their guns. The _Merrimac_ could fire three times to her one, but not a ball took effect. It was like a battle in a cloud. "Why are you not firing?" asked Lieutenant Jones of a gun captain. "Why, powder is getting scarce," he replied, "and I find I can do that whiffet as much harm by snapping my finger and thumb every three minutes." Then Lieutenant Jones tried to sink the _Monitor_. Five times the great iron monster came rushing up upon the little Yankee craft, but each time it glided easily away. But when the _Merrimac_ came up the sixth time Captain Worden did not try to escape. The _Monitor_ waited for the blow. Up rushed the _Merrimac_ at full speed and struck her a fierce blow. But the iron armor did not give way, and the great ship rode up on the little one's deck till she was lifted several feet.