Abstract: There is disclosed a unitary vacuum transducer or pump capable of obtaining a high degree of vacuum using standard shop compressed air fed to a single inlet in the transducer from a single source of compressed air, each venturi tube having compressed air supply means associated with said inlet and terminating in a jet-producing nozzle. The transducer comprises two or more venturi tubes arranged in series with the entrance section of one venturi tube being connected to the exit section of another smaller venturi tube the entrance section of which is connected to the exit section of a yet smaller venturi tube or to the orifice of a vessel containing air or other gas to be rarefied.