Bowen's double hemisphere was issued in 1744 in his atlas of the world. It was then used extensively by the author in both his own later atlases and other publications for which he was contracted to supply maps, the most notable of which was John Harris's expanded re-issue of the "Complete Collection of Voyages and Travels" published 1744-8.

Geographically, the map is based on French maps of the period. The Pacific Northwest is based mostly on the theory of the revised Guillaume de L'Isle map, with the coast north of California left mostly unknown with the exception of a few vague indications that there may be inlets which could lead to a large bay or waterway resulting in a Northwest Passage. On the other side of the North Pacific, Bowen shows the mythical Gamaland, reported by the grandson of the famed explorer Vasco di Gama; Joao di Gama sailed across the Pacific on a far more northerly latitude than was customary and sighted a new coastline, possibly Hokkaido, or one of the Aleutian Islands and upon its report, it was named it after him.



The map also bears a central area across the oceans, showing the prevailing direction of the trade winds. This was researched by the eminent astronomer Sir Edmund Halley and was first introduced on charts by Mount and Page in the early 18th century but popularised by Hermann Moll. Africa, Europe and the Middle East are orthodox for the period, drawing again mainly on French sources. The Far East draws mostly on Dutch and English sources, with Japan based on the map by Engelbert Kaempfer and the mythical Dutch Company's Land, now shrunk from a vast unknown landmass possibly linking Asia and North America, to a tiny island east of Japan. Yesso, is now more or less correct as a large island north of Japan. Interestingly, Bowen follows a mainly 18th century doctrine of marking the body of water north and to the west of Japan as the "Sea of Korea" a point of contention to this day.

New Holland or Australia is another point of great geographical curiosity on this map, with Bowen speculating that Dutch voyages, culminating with Tasman's discoveries in New Holland or Australia linked both with New Guinea and with van Diemen's Land or modern Tasmania, thus forming one large landmass. This was not an unknown theory in the mid-18th century but it was certainly not universal; Bowen was copying a map engraved on the floor of the Town Hall of Amsterdam which initially showed this theory in the 1660s. Another curious landmass is present east of Australia entitled "H. Ghost Land". This is a translation of the French "Terre d'Esprit" which in itself is a translation of "Australia del Espiritu Santo" named by the Portuguese explorer Pedro Fernandez de Queiros when he landed in the archipelago of Vanuatu, formerly the New Hebrides, and became convinced that he had found the mythical Great Southern Land in 1606. The island on which he landed is still called Espiritu Santo today.



Although the map attempts to emulate French scientific mapping to suit the Age of Enlightenment in the 18th century, aesthetically, it harks back far more to the Dutch Golden Age of the 17th century, with four figures set within panoramas representing continents on each corner, a central cartouche separating the land and the sea on the upper centre and a creation image on the lower centre. The style of engraving and figures are particularly reminiscent of the highly successful maps issued by Pieter van der Aa approximately thirty years earlier.



The example offered for sale on this occasion is a 1766 edition.

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