*John Harrison solved the longitude problem, but he was never actually paid the prize he thought he deserved. In Longitude (1995), Dava Sobel makes a persuasive case that Harrison was unfairly deprived of his prize by the machinations of envious astronomers. But there’s an alternative view: that because Harrison jealously guarded the details of how his clock worked, he did not provide a practical solution to the longitude problem—he merely demonstrated that he had such a solution within his gift.