Solidoporting from a base projector to a field target was a standard means of moving goods across the vast distances of Venus. Any inanimate object could be 'ported; animate beings couldn't because the process involved certain minor but distressing molecular changes in protoplasm. A few people had found this out the hard way when 'porting was first introduced.
Morrison waited. The aerial whirlpool became a mouth three feet in diameter. From the mouth stepped a chrome-plated robot carrying a large sack.
"Oh, it's you," Morrison said.
"Yes, sir," the robot said, now completely clear of the field. "Williams 4 at your service with the Venus Mail."
It was a robot of medium height, thin-shanked and flat-footed, humanoid in appearance, amiable in disposition. For twenty-three years it had been Venus's entire postal service—sorter, deliverer, and dead storage. It had been built to last, and for twenty-three years the mails had always come through.
"Here we are, Mr. Morrison," Williams 4 said. "Only twice-a-month mail call in the desert, I'm sorry to say, but it comes promptly and that's a blessing. This is for you. And this. I think there's one more. Sandcar broke down, eh?"
"It sure did," Morrison said, taking his letters.