Very well-written and researched. I really enjoyed reading this, though it took me awhile. These 19th century gentlemen certainly had fascinating lives. They just decided, "Well, I guess I'll learn some engineering," or "I guess I'll be an architect." And then they did, no four year degree required....
I'm a fan of Rybczynski's writing and Olmsted's parks, so this was pure bliss to me.