Batteries 20 may be conveniently mounted in {HEAD ~ a spiral formed rod} 22 mounted on {TAIL ~ the framework} of the apparatus 
mounted on
Batteries 20 may be conveniently mounted in { HEAD ~ a spiral formed rod } 22 mounted on { TAIL ~ the framework } of the apparatus
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH