Representative Trey Gowdy, the committee chairman, ended the marathon Benghazi committee hearing by peppering Hillary Rodham Clinton with a barrage of questions about the emails that she had turned over.

His forehead soaked in sweat, Mr. Gowdy demanded that Mrs. Clinton explain how she came up with the figure that 90 to 95 percent of her emails were already in the possession of the State Department and questioned why she gave different answers to different people about her private email server.

Mr. Gowdy then probed Mrs. Clinton about how she could know if she had really turned everything over, if more private emails had emerged since she first made that proclamation.

“Was it a mistake for the four years that you had that email arrangement?” Mr. Gowdy asked. “Was it a mistake for four years that you kept the public record to yourself, or has it manifest itself as a mistake in the last six months?”

Mr. Gowdy and Mrs. Clinton did have a brief light moment when he joked about the high price of her lawyers.

“I’m well aware of that mister chairman, and the clock is ticking,” Mrs. Clinton said.

Mr. Gowdy offered to pay Mrs. Clinton if he could ask her one more question. Moments later he thanked her for her patience and let her go.

“With that, we will be adjourned,” he said.