I've always appreciated AO's geography books, and we've dutifully done our mapwork with each one. However, I wanted my children to understand the principles behind both latitude and longitude and why each was critical (even moreso than today) for navigation in years past. So I was pleased when I ran across (in our church library) Louise Borden's Sea Clocks: The Story of Longitude.
And what a story! Although sea navigators had long been able to ascertain their whereabouts north or south of the equator, thanks to lines of latitude and their handy sextants, they had no idea of where they were east or west of their home port. Ships tended, then, to stick to well-known routes along lines of latitude -- which were well known to pirates, as well. Pirates weren't the only difficulty, either. Storms blew ships off course, adding weeks or months to a journey's length. Crews often ran out of rations long before they found their way home. Not only were businessmen and investors losing their money, but sailors were losing their lives. It was a serious problem, and it seemed impossible to solve.
Enter John Harrison (1693-1776), a mechanical genius with no formal education but plenty of determination and perseverance. A clockmaker by trade, Harrison spent most of his adult life attending to this problem of longitude by devising and building five different sea clocks, forerunners of the chronometer. He also endured a long battle with the Royal Society and the Board of Longitude for recognition of his life's work to such a degree that even King George III himself got involved in the predicament.
The book is designed as a picture book, but unlike many of that genre, the text counts more than the illustrations here. Borden does a good job of explaining just enough technical details to engage readers without boring, confusing, or alienating them. Since I tend to get bogged down in too much mechanical detail, I was happy with her descriptions.
We enjoyed this book very much and came away with a genuine respect for John Harrison and his accomplishments, which are nothing short of astonishing. We also made note of the back matter, which tells where Harrison's sea clocks are now on display. They made the list of "must-sees" when we go to England in the next couple of years.