kiln vs oast

kiln

noun
  • An oven or furnace or a heated chamber, for the purpose of hardening, burning, calcining or drying anything; for example, firing ceramics, curing or preserving tobacco, or drying grain. 

verb
  • To bake in a kiln; to fire. 

oast

noun
  • A kiln for drying tobacco, malt and especially hops. 

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