curvilinear vs spheric

curvilinear

adj
  • Having bends; curved; curvilineal. 

  • Formed by curved lines. 

spheric

adj
  • Spherical. 

  • Of or relating to the heavenly orbs, or to the sphere or spheres in which, according to ancient astronomy and astrology, they were set. 

How often have the words curvilinear and spheric occurred in a corpus of books? (source: Google Ngram Viewer )