Flavio Gioia

Flavio Gioja or Gioia (c. 1300) was reputed to be an Italian mariner and inventor, supposedly a marine pilot, and has traditionally been credited with perfecting the sailor's compass by suspending its needle over a fleur-de-lis design, which pointed North, also enclosing the needle in a little box with a glass cover.

Gioia was also said to have introduced the fleur-de-lis design in deference to Charles of Anjou, the French king of Naples.)

Flavio Gioia's birthplace is alternately given as Amalfi, Positano, Naples, and, Gioia, a town in Apulia, hence the derivation of the reputed surname.

The lunar crater Gioja is named after him.

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