Leonardo's world map

Da Vinci developed the concept of dividing the surface of the globe into eight spherical equilateral triangles based on his botanical drawings.

[3] Some critics believe that the existing map was not really an autograph work, since the precision and expertise in the drawing does not reflect the usual high standards of da Vinci.

[7] Since the discovery of the Ostrich Egg Globe, Stefaan Missinne has written a book[8] in which he argues that the authorship of the design of the map is Leonardo's.

The manuscript world map intended to be glued has been attributed to Melzi, because of the type of lettering used and because of his proximity to Leonardo during his stay in France.

The oceans do bear names and the spelling has only a few “mistakes,” i.e. variants such as “Brazill” ending with a double “l.” The letter “z” on C (abo) B (ona) speranza differs considerably from Leonardo’s types of “z.” which is also the case for the “b” in “Abatia”.

",[14] or Keunig (1955) being more precise: "..by one of his followers at his direction.."[15] The subject of mathematical analysis of Leonardo's octant globe has been considered very briefly in scientific publications.