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