Immediately after my retirement in May 2004 from the electrical engineering department of the University of New Hampshire (UNH), my wife Pat and I moved from New England to the beautiful state of Tennessee. We came back to New Hampshire the very next year (we missed our kids), but while in Tennessee I wrote this book. While doing that I received a lot of support from the tolerant waitresses at Donna Akey’s Plaza Restaurant in Tellico Village, Loudon, who cheerfully kept my coffee cup full even as I sat, nearly every day (sometimes for hours), scribbling away with my pen on a pile of manuscript pages. (Every now and then I would buy a hamburger, too.) They were all too polite to ask what I was up to, but now they know.
Once I had that pile of paper big enough, I sent it to my longtime math editor at Princeton University Press, Vickie Kearn, who encouraged me to finish the book, and who sweetened the offer with a contract to publish it if I actually did get the job done. During those long, quiet writing days in Tennessee I occasionally found that, while the surroundings were gorgeous, there were no technical libraries available (unless I was willing to risk my life dueling with truckers on Interstate 40 to get to the University of Tennessee Library in Knoxville, 30 miles away). I am therefore grateful to two library friends back at UNH, Professors Barbara Lerch and Emily Poworoznek, who sent me copies of papers I could not have obtained otherwise. Two other librarians who deserve my thanks are Marjorie McNinch and