Consider a steam engine, run by anti-matter reactions, starting in the 19th century. Also, consider the idea of anti-ice as a method of storage for vast quantities of energy. Throw in Victorian Era events, mix thoroughly, but don't let the anti-ice melt too soon.
Hard sci-fi, without Baxter's usual "throw odd quantum physics terms around like hotcakes" style. A much easier read than "Vector Diagrams" by the same author.