Fine Structure is noted for its highly nonlinear, not to say garbled, presentation.
As part of work on a (now abandoned) end-to-end rewrite of the story, I assembled a chronological listing of the chapters according to the in-universe timeline, which I found made somewhat more sense.
Read from top to bottom.
Remember to ignore the "Next: ..." links at the end of each chapter! Those will take you to next chapter in publication order, not the next chapter in chronological order.
Towards the end, the timeline starts jumping around even within the confines of a single chapter. Also, I think some characters appear before being introduced. Still, without dissecting the chapters themselves this is about as logical as the order gets.