Excellent illustrations and a good historical sweep through the first century or so of the history of the Underground. Fascinating when describing how the Inner Circle was created, how deep-level tubes supplemented cut-and-cover. Describes the golden era of Metroland in detail, and shows the important part the Tube played in London's growth. Starts to become a little less interesting in the post-WW2 era - the politics, construction and technology of the Victoria and Jubilee lines are dealt with rather too briskly. As an interested non-expert, I felt this book contained pretty much everything I wanted to know and was surprisingly readable.