Inspiration: I spent most of the 1980s in graduate school, working on a Ph.D. in history. One of the toughest tasks a grad student faces is finding a dissertation topic. It's not that easy: she has to find a topic that's reasonably fresh and hasn't been analyzed to death. But she also has to choose one that can be turned into a book later, and (most important) will hold her interest for the two or three years it will take to research and write. I found my topic by accident. I wrote my master's thesis (the shorter research project that precedes a dissertation) about fire fighting and waterworks in small cities in the late nineteenth century. While I researched those subjects, I kept coming across papers and articles by "sanitary engineers" who wrote about household plumbing, which was, in the 1880s and 1890s, a relatively new technology. I scanned those reports but didn't pay too much attention to them; after all, my focus was firefighting and water supply, not toilets and sinks. I wrote the thesis and then finished my classroom course work. The next step was to write a dissertation. I had to find a dissertation topic--and fast! I came up with and then discarded one idea after another. Nothing seemed to "fit." Then one night I woke from a sound sleep, sat bolt upright in bed, and said "Plumbing. I'll write about plumbing." Having settled the issue, I flopped back and returned to my slumber. The next morning, I was awake for fifteen or twenty minutes before I remembered what had happened. Plumbing, I thought to myself. Hmmm. What a great idea! The rest, as they say, is history.