Convert from microinch to league

Unit Definition (microinch)
The microinch is a common imperial unit of distance equal to one millionth of an inch, or 25.4 nanometers (nm). The microinch is used for precise machining tolerances and also to describe the roughness of surfaces.

Unit Definition (league)
The league became a common unit of measurement throughout western Europe, although its length varied greatly from region to region. It was originally intended to represent the distance a person could walk in an hour. In many cases it was equal to 3 miles, (note that the definition of a mile also varied from region to region). At sea, the league was often equal to 3 nautical miles, which is 1/20 degree or 5556 meters (metres). In the USA and Great Britain, the league is defined to be 3 statute miles (~4828.03 meters) on land, or 3 nautical miles at sea.