Come, I will conceal nothing from you: The Properties of Rooftop Air is too short to be anything except a short story or novella. But it’s by Tim Powers, and it draws on The Anubis Gates, and if you’ve never read the latter then do yourself a favor and go buy that first. That’s a Book of the Week all on its own.
Tim Powers’ The Anubis Gates is one of the best time travel novels ever written. I don’t say that sort of thing lightly. What makes it stand above most of the rest of this particular genre is in Powers’ uncanny ability to find hollowed-out places in the historical records where one is able to pour in a story or three. You are left with the sense that while things might not have turned out the way that he portrayed them (usually a safe bet, since he writes fantasy novels), but they should have turned out that way and there’s no way to disprove it now anyway. This was the first one of his that I read, and I’ve been buying Tim Powers on sight ever since.
And so, adieu to Carter and Lovecraft.