brooding vs cogitation

brooding

noun
  • A spell of brooding; the time when someone broods. 

adj
  • Broody; incubating eggs by sitting on them. 

  • Deeply or seriously thoughtful. 

cogitation

noun
  • The process of cogitating; contemplation, deliberation, reflection, meditation. 

  • A carefully considered thought, idea, notion. 

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