Some horologists consider the Jefferys timepiece the first true precision watch. Harrison’s name is all over it, metaphorically speaking, but only John Jefferys signed it on the cap. (That it still exists, in the Clockmaker’s Museum, is something of a miracle, since the watch lay inside a jeweler’s safe in a shop that took a direct bomb hit during the Battle of Britain, then baked for ten days under the building’s smoldering ruins.)
