The whole question of the regime of rivers and lakes is sometimes treated under the name hydrography, a name used by some writers in the sense of marine surveying, and by others as synonymous with oceanography.
The hydrography of the campo region of Minas Geraes is extremely complicated.
In 1693 he was engaged to publish a second volume of the Neptune francais, which was to include the hydrography of the Mediterranean.
In 1713 he was appointed to succeed his father as professor of hydrography.
The work of the Franco-Liberian delimitation commission in1908-1909cleared up many points connected with the hydrography of the country.