An apparatus in accordance 6 wherein said supply means comprises {HEAD ~ an annular chamber} surrounding {TAIL ~ said evacuation chamber}, means for supplying said drive medium to said annular chamber under pressure and a ring nozzle means for feeding the drive medium from said annular chamber to said evacuation chamber at a supersonic speed 
surrounding
An apparatus in accordance 6 wherein said supply means comprises { HEAD ~ an annular chamber } surrounding { TAIL ~ said evacuation chamber } , means for supplying said drive medium to said annular chamber under pressure and a ring nozzle means for feeding the drive medium from said annular chamber to said evacuation chamber at a supersonic speed
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH