{TAIL ~ A conduit} 78 interconnects cannisters 72, 74 at the bottom of {HEAD ~ one end} 
{ TAIL ~ A conduit } 78 interconnects cannisters 72 , 74 at the bottom of { HEAD ~ one end }
TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD