{TAIL ~ Apparatus} 36 includes a tube 37, having a pump 38 at {HEAD ~ one end} and gas entry pipes 39 and 40 shown for convenience as being at the other end 
{ TAIL ~ Apparatus } 36 includes a tube 37 , having a pump 38 at { HEAD ~ one end } and gas entry pipes 39 and 40 shown for convenience as being at the other end
TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH