inner tube vs launder

inner tube

noun
  • An inflatable rubber tube inserted into the casing of a pneumatic tyre/tire. 

  • Synonym of swim ring 

launder

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

  • A gutter (for rainwater). 

  • A trough used by miners to receive powdered ore from the box where it is beaten, or for carrying water to the stamps, or other apparatus for comminuting (sorting) the ore. 

verb
  • To disguise the source of (ill-gotten wealth) by various means. 

  • To wash; to wash, and to smooth with a flatiron or mangle; to wash and iron. 

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