sluice box vs trough

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. 

trough

noun
  • A rectangular container used for washing or rinsing clothes. 

  • A gutter under the eaves of a building; an eaves trough. 

  • A linear atmospheric depression associated with a weather front. 

  • A long, narrow container, open on top, for feeding or watering animals. 

  • A long, narrow depression between waves or ridges; the low portion of a wave cycle. 

  • A channel for conveying water or other farm liquids (such as milk) from place to place by gravity; any ‘U’ or ‘V’ cross-sectioned irrigation channel. 

  • Any similarly shaped container. 

  • A short, narrow canal designed to hold water until it drains or evaporates. 

  • low turning point or a local minimum of a business cycle 

verb
  • To eat in a vulgar style, as if from a trough. 

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