I'm looking for the title of a fantasy novel I started reading but never finished. I would have read it in the late 90's/early 00's and I checked out of a library in the UK. Here a the plot details I remember:
The setting was a series of islands that floated in the sky on which were built various cities and towns. The islands did not float above anything; as far as the characters were concerned, these flying islands were all there was to the world and they were surrounded by clouds, obscuring any 'ground' there might be. People travelled between the islands either on the backs of dragons or via floating airships. At one point there is a digression where the protagonist justifies using an airship over a dragon (or vice versa) and talks about the pros and cons of each method.
Below this human occupied layer of islands was a second layer of floating islands inhabited by some kind of dwarf like creatures who worked constantly to maintain some form of mysterious machine. They called the machine something ridiculous like the 'Kicksi-Winsi'. Neither layer of islands was aware of the others existence.
It's possible there was another race that lived with the humans. Possibly the humans favored airships and the other race rode dragons? I may be misremembering this and it may have just been different human cultures.
I also recall that the novel had two authors because I remember my Dad telling me he didn't think a novel with two authors would be any good.