Fascinating study in the comparative cartography of the West Coast of North America, from the Straits of Anian to Cabo San Lucas and the southern tip of Baja California.
The work consists of extracts from two maps, both reportedly done by Visscher in the 1612 and 1641 respectively and with information derived from Mercator and Plancius. The larger map prominently shows the Strait of Anian, Anian Regnum, Quivira Regnum, the Sierra Nevada, Nova Albion, Totonteac Regnum, Tolm Regnum and a coastal detail which includes over 30 coastal place names, including Mendocino, San Miguel (San Diego), Cape Fortuna, I. De Paxaros (Catalina?), and many mythical/ephemeral place names.
The smaller map also shows the Straits of Anian, but depicts an open sea above, clearly portending a NW Passage in the Arctic Circle. The NW Coastline differs radically, and only Anian Regnum and Quivira Regnum are located, that later considerably south of the location on the larger map. The smaller map includes a similar number of coastal placenames, but includes several important ones not listed on the larger map, including C. Blanco (3 times), C. de San Francisco and los Farilones, but omits any significant effort to depict bays.
Diderot's work is part of a 10 map supplement to his Encyclopedia, and provides one of the most fascinating studies in contemporary comparative cartography which can be obtained by collectors, much of which is dedicated to the NW Coast.
Didier Robert de Vaugondy (ca. 1723-1786) was the son of prominent geographer Gilles Robert de Vaugondy and Didier carried on his father’s impressive work. Together, they published their best-known work, the Atlas Universel (1757). The atlas took fifteen years to create and was released in a folio and ¾ folio edition; both are rare and highly sought-after today. Together and individually, father and son were known for their exactitude and depth of research.
Like his father, Didier served as geographer to King Louis XV. He was especially recognized for his skills in globe making; for example, a pair of his globes made for the Marquise de Pompadour are today in the collection of the Municipal Museum of Chartres. Didier was also the geographer to the Duke of Lorraine. In 1773, he was appointed royal censor in charge of monitoring the information published in geography texts, navigational tracts, and travel accounts.