Herculean vs well-knit

Herculean

adj
  • Of extraordinary might, power, size, etc.; suggesting Hercules in size or strength. 

  • Requiring a huge amount of work; of extraordinary difficulty. 

well-knit

adj
  • Firmly constructed and held together 

How often have the words Herculean and well-knit occurred in a corpus of books? (source: Google Ngram Viewer )