After telling his story to his guests, how does the TT reassure himseld that the story is really true?

The TT needs to go and see his machine to remind himself of the truth of his tale,

The Time Traveller put the lamp down on the bench, and ran his hand along the damaged rail. “It's all right now,” he said. ”The story I told you was true. I'm sorry to have brought you out here in the cold.” He took up the lamp, and, in an absolute silence, we returned to the smoking-room.