"Whatever you call yourself—listen to me. You're going back in the time machine and shift that rock back to its original position. Once that's done—"
"If I go back again, I get another hundred."
"How can you talk of money at a time like this?"
"What's the difference between this and any other time?"
"Why, here I am married, my work interrupted and you chatter about—Oh, all right. Here's the money." The professor tore his checkbook out and hastily scribbled on a blank. "Here you are. Satisfied?"
McCarthy puzzled over the check. "This isn't like t'other. This is on a different bank—The Cotton Growers Exchange."
"That makes no important difference," the professor told him hastily, bundling him into the time machine. "It's a check, isn't it? Just as good, believe me, just as good."
As the little man fiddled with dials and adjusted switches, he called over his shoulder. "Remember, get that rock as close to its original position as you can. And touch nothing else, do nothing else."
"I know. I know. Hey, prof, how come I remember all these changes and you don't, with all your science and all?"
"Simple," the professor told him, toddling briskly out of the machine. "By being in the past and the time machine while these temporal adjustments to your act made themselves felt, you were in a sense insulated against them, just as a pilot suffers no direct, personal damage from the bomb his plane releases over a city. Now, I've set the machine to return to approximately the same moment as before. Unfortunately, my chronotransit calibrations can never be sufficiently exact—Do you remember how to operate the apparatus? If you don't—"