Page:Popular Science Monthly Volume 15.djvu/169

Rh was not till the middle of the eighteenth century that, chiefly through the influence of D'Anville and the Cassinis, the precise difference of 20 was definitively adopted. The well-earned fame of the French geographers gave to their determination authority throughout Europe, and

all the nations accepted this distance and the meridian of Ferro, except England, which fixed her first meridian at St. Paul's in London, and later at Greenwich. In France the meridian of Paris came to be reckoned as first meridian from the publication of Cassini's map. The