John Harrison (1693–1776) was a self-taught clockmaker who had a profound impact on mapmaking and ship navigation thanks to his work developing the marine chronometer. This biography describes his life from childhood, when he would take apart and reassemble old watches, to his final days, when he was finally recognized for his achievements. His life’s work helped generations accurately determine longitude. These PUBBLYs have professionally produced audio and sound effects, as well as animated dialog boxes. The panels of the graphic novels are presented one or two sliding panels at a time so that readers can see and experience the story fully and to let the story unfold slowly over time. Teacher’s guides (downloadable PDFs) contain background information, vocabulary, comprehension questions, and discussion guides.