From Shelby Foote’s The Civil War: Fort Sumter to Perryville (261):
[On 9 March 1862, the world’s first battle between ironclad warships took place. The smaller and nimbler Monitor was able to outmaneuver Virginia, but neither ship proved able to do significant damage to the other. Catesby Jones, commander of the Virginia] gave the Monitor everything he had given the wooden warships yesterday, and more: to no avail. When he tried to ram her, she drew aside like a skillful boxer and pounded him hard as he passed. After a few such exchanges, the crews of his after-guns, deafened by the concussion of 180-pound balls against the cracking railroad iron, were bleeding from their noses and ears. Descending once to the gundeck and observing that some of the pieces were not engaged, Jones shouted: “Why are you not firing. Mr. Eggleston?” The gun captain shrugged. “Why, our powder is very precious,” he replied, “and after two hours incessant firing I find that I can do her just about as much damage by snapping my thumb at her every two minutes and a half.”