If you're interested in this, read Dava Sobel's book, "Longitude". Harrison was the archetype of the stubborn, self-educated genius that stuck to his ideas, fought the system for most of his life, and then changed the way the world worked. Seriously entertaining read. You'll walk away with an appreciation for timekeeping and knowing how to find your latitude and longitude with an accurate watch, a chart of times at high noon in Greenwich, and a few odds and ends (like a stick, a nail, and a clouded view of the sun).