An English world map after the Longitude Act

A double-hemisphere map of the world with four further spheres on different projections, an armillary sphere flanked by two figures (one being Hercules) and allegorical figures of the four continents around the title. On the map California is featured as an island (although not on two of the smaller spheres), 'Jesso' is joined to mainland Asia, and Australia is joined to New Guinea via Carpentaria. Unusual features on this map are the faint outlines offering alternative coastlines around the countries furthest from Europe. The Longitude Act of 1714, in which a prize of £20,000 was offered for an accurate method of measuring longitude at sea, highlighted the fact that the exact locations of countries on the other side of the world had yet to be determined. This map displays an unusual admission of lack of certainty by a cartographer! Although this example is marked 'Revis'd' we have been unable to trace an earlier version. George was made Prince of Wales in 1714, and came to the throne of England in 1727 as George II.