inlayer vs sluice box

inlayer

noun
  • A trough or channel carrying water to the wheel of a watermill. 

  • One who inlays. 

sluice box

noun
  • A box with riffles along the bottom, used to trap heavier gold particles as water washes them and the other material along the box. 

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