SELECTING A FIRST MERIDIAN. 



157 



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 geog- 

 raphers gave to their determination authority throughout Europe, and 



all the nations accepted this distance and the meridian of Ferro, ex- 

 cept 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 



