I found his "The Professor and the Madman" to be quite good. I participated in a panel discussion on the book for our local PBS affiliate, and the consensus of all the historians was that it was a well-done bit of research and writing. And it gave me the opportunity to bring my first edition Volume One of the Oxford English Dictionary as an on-air prop: it was published in 1888 and is about six inches thick; it covers the letters A and B!