Three major events contributed to the spectacular renaissance of cartography in Europe around 1500—the rediscovery and translation into Latin of Ptolemy's Geographia, the invention of printing and engraving, and the great voyages of discovery. This renaissance was manifested by the work of Gerardus Mercator in the first modern world atlas, published in 1570 by Abraham Ortelius, and by the decorative, paintinglike maps of the French Sanson family (17th cent.). Improvements in the methods of surveying and increased emphasis on accuracy led to the noted work in the 18th cent. of the Frenchmen Guillaume Delisle and J. B. B. d'Anville, the founders of modern cartography. After 1750 many European governments undertook the systematic mapping of their countries. The first important national survey was made in France (published 1756), followed by the Ordnance Survey of Great Britain (published 1801) and the topographic survey of Switzerland (organized 1832). In the United States the U.S. Geological Survey (established 1879) has mapped much of the country on varying scales.