LaBorde, Jean Benjamin de
Jean-Benjamin De LaBorde (1734-1794) was best known as a musician from the age of 14, but was also a historian and cartographer(a) . In his Histoire abregeee de la Mer du Sud[1266], it appears he was the first to suggest a sunken continent in the South Pacific with New Zealand and other island groups being today’s remnants of Plato’s lost land.
Unfortunately, his musical and scientific interests were curtailed when his association with Louis XV led him to the guillotine.
(a) https://historic-cities.huji.ac.il/italy/syracuse/maps/laborde_1800_syracuse.html