blow tube vs blowpipe

blow tube

blowpipe

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

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

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