Carry On, Mr. Bowditch

In Carry on, Mr. Bowdith, Nathaniel Bowditch had to give up his cherished dream of a Harvard education to serve a nine-year apprenticeship in a ship chandlery, but he never stopped studying.  His uncanny ability with figures, his interest in helping the common sailors to understand the elements of navigation, and his perseverance in checking through masses of figures finally resulted in the publication of The American Practical Navigator, a book which is still the "bible" of navigation.