Or maybe to the mule train, though in operation you're sure to be reminded of the safari bearers in old movies, trudging stolidly along behind the White Hunter with bales of supplies on their heads. The thing is a pair of metal legs exactly as long as your legs, with equipment on the top and an umbilical cord attaching the contraption to your lower spine. What it does is provide you with the capability of living on the surface for four weeks instead of the five days you get from your Venus-lung The medico who sold me mine had me laying right there on his table with my back laid open so he could install the tubes that carry air from the tanks in the tagalong into my Venus-lung. It was a golden opportunity to ask him to check the eye. He probably would have, because while he was hooking me up he inspected and tested my lung and charged me nothing. He wanted to know where I bought it, and I told him Mars. He clucked, and said it seemed all right: He warned me not to ever let the level of oxygen in the lung get too low, to always charge it up before I left a pressure dome, even if I was only going out for a few minutes. I assured him that I knew all that and would be careful. So he connected the nerves into a metal socket in the small of my back and plugged the tagalong into it. He tested it several ways and said the job was done.

And I didn't ask him to look at the eye. I just wasn't thinking about the eye then. I'd not even gone out on the surface yet. So I'd no real occasion to see it in action. Oh, things looked a little different, even in visible light. There were different colors and very few shadows, and the image I got out of the infraeye was fuzzier than the one from the other eye. I could close one eye, then the other, and see a real difference. But I wasn't thinking about it.

So I boarded the blimp the next day for the weekly scheduled flight to Lodestone, a company mining town close to the Fahrenheit Desert. Though how they were able to distinguish a desert from anything else on Venus was still a mystery to me.