Longitude - Dava Sobel
A fascinating look at a defining moment in technological development. Full of intrigue, double-crossing, maths, and science.
It cracks along at a fair pace, sometimes lightly skipping over details. I would gladly have read this if it were twice the length. Not a bad thing for a book to leave you wanting more.
The only weakness is a lack of diagrams and maps. Happily, there is an illustrated edition, which I will check out in due course.