 Why is the air inside the machine not stale on the return trip like it had been on the prior trip?
[Transcriber's Note: This etext was produced from Galaxy Science Fiction February 1951. You will, you know, so why quibble about it? At least, you always have ... or do ... or will. You'll get used to it, of course, but it will take about thirty years. It's a real wrench when a man meets himself for the first time. Yes, it'll be pretty obvious it must be a time machine. You've seen it, just a small little cage with two seats, a luggage compartment, and a few buttons on a dash. You'll be puzzling over what I'll tell you, and you'll be getting used to the idea that you are the man who makes atomic power practical. You can see a sort of foggy nothing surrounding the cockpit; it is probably the field that prevents passage through time from affecting us. You are completely outside of time and space, as best you can guess how things are. Then it comes to you slowly that you're actually traveling in time. "Maybe it's no dimension—or it might be the fifth; if you're going to skip over the so-called fourth without traveling along it, you'd need a fifth. There may have been a time when you did invent the machine—the atomic motor first, then the time-machine. I figured out once that such a universe would need some seven or eight time and space dimensions. Maybe there is no machine, and it's just easier for us to imagine it. Anyhow, you sit there, watching nothing all around you, and no time, apparently, though there is a time effect back in the luggage space. That means you either carry a small time field with you, or you are catching a small increment of time from the main field. I'm smoking, and so are you, and the air in the machine is getting a bit stale. You suddenly realize that everything in the machine is wide open, yet you haven't seen any effects of air loss. Out there is neither time nor space, apparently. You still feel gravity, but I can't explain that, either. Maybe the machine has a gravity field built in, or maybe the time that makes your watch run is responsible for gravity. You feel a dankish sort of air replace the stale air, and you breathe easier, though we're in complete darkness, except for the weak light in the machine, which always burns, and a few feet of rough dirty cement floor around.
 Because there is only one Jerome smoking inside the machine.
 Because the generator is working and clearing the air.  Because there is a clearer air flow now with the retrieval of the generator.  Because no one is smoking inside the machine.  Because there is only one Jerome smoking inside the machine.