This is the extremely rare first state of Dudley's chart of the coast of Baja California and California. It covers the coast from approximately Bahia Bellenas to G. di S:Pietro (Monterey Bay). Beautifully engraved by Antonio Francesco Lucini, it records various magnetic deviations and indicates the prevailing winds and ocean currents. Presented on Mercator's projection and on a larger scale than previous maps of the region, it includes numerous fictitious place names. While it has been suggested that Dudley used information from his friend, Sir Francis Drake, there is no evidence to support that theory. According to Burden and Wagner, the source is most likely manuscript maps by John Daniell, now in the Biblioteca Nazionale, that Dudley probably brought with him from England when he moved to Florence. The map is embellished with distinctive calligraphy (alla cancellaresca), a fine cartouche, and sailing ships and a large compass rose. Printed on two joined sheets as issued.

Robert Dudley was the first Englishman to produce a sea atlas, Dell' Arcano del Mare (Secrets of the Sea). He introduced a totally new style for sea charts in the atlas with only lines of latitude and longitude and no rhumb lines. The charts were meticulously compiled from original sources and were both scientific and accurate for the time. This important atlas was the first sea atlas of the whole world; the first to use Mercator's projection throughout; the earliest to show the prevailing winds, currents and magnetic deviation; and the first to expound the advantages of Great Circle Sailing. In an introductory leaf found in one copy in the British Library, the engraver states that he worked on the plates in seclusion for twelve years in an obscure Tuscan village, using no less than 5,000 pounds of copper for the printing plates. It was only issued in two editions and the maps are rarely seen on the market.

References: Burden #283; Wagner (NW), pp 81 & 119-22, #352c; Shirley (BL Atlases) #M.DUD-1a [145].

Condition: B+

Overall very good on watermarked paper with just a hint of faint foxing along the lower centerfold. Remnants of hinge tape on verso.