Lopez's rare and detailed chart of The Bahama Channel.

To the upper right is an extensive text block providing information on the chart. The islands were it state"discovered by Columbus". The text goes on to mention the previous charts which Lopez has consulted,noting a great difference between them: "as not only is there a difference in number of islands, the shape of islands, but even in the names". The best source, Lopez says, is Thomas Jeffreys map of the region of 1777. The map includes a reference to Harbor Island in Spanish (Isla d'Abra, ú Harbour).

Tomas Lopez de Vargas Machuca (1731-1802) was a Spanish publisher and the leading cartographer of the age. He studied with Jean-Baptiste Bouguignon d'Anville in Paris, before returning to his native Madrid in 1760, when he established the only independent cartographic publishing house in Spain in 1760. He began making maps for the Bourbon kings and became Royal Geographer to King Carlos III in 1780. He was even authorised to create a geographic agency for the secretary of state in 1795.