blowpipe vs blowtube

blowpipe

noun
  • a weapon through which darts may be shot by blowing; a blowgun 

  • a narrow tube through which a jet of air is directed onto a flame; used in the analysis of minerals etc and in jewelry manufacture 

  • a long narrow pipe, rotated in the hands, upon which glassware is blown 

blowtube

noun
  • A blowgun. 

  • A blowpipe (used in metallurgy, etc.). 

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