hydraulic vs hydrographic

hydraulic

adj
  • Pertaining to water. 

  • Related to, or operated by, hydraulics. 

verb
  • To mine using the technique of hydraulic mining. 

hydrographic

adj
  • Of or pertaining to hydrography. 

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