This book is less about the history of time travel in fiction and more about the concept of time in mostly the 19th and 20th century : how it used to be perceived and the philosophical and scientific theories around it. I adored about the first third of the book, because it focused very much on the developements that caused the idea of time travel and the discussions this idea sparked. There was a lot of information I found to be fascinating and even mindblowing in relation to history and the science fiction genre. However, afterwards there was so much time dedicated to scientific time theories that felt dragging and repetitive after a while, and, while I wasn't entirely disinterested, it wasn't what I read the book for. Towards the end, it does pick up the topic of time travel media again, going into examples and paradoxes, I had just expected that the whole book was more focused on that. I thought it would discuss changes and differences in fiction dealing with time travel and what cultural and maybe scientific developments led to them, but instead it used the concept of time travel as an excuse to discuss "what is time?". I think this is a book interesting for people that are into the history of ideas, science and philosophy, and less for readers that want to learn about media or literature history. I wish I've known that, for I was primarily reading this as inspiration for what time travel books ro read next. Still, I learned a lot of fascinating stuff, the appendix lists a lot of works I can get into and it was an enjoyable read. If the first third wasn't as brilliant I wouldn't rate it as highly, though, since the majority of the book felt more like a 3 star read for me.